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Intervention Review

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Interventions for preventing excessive weight gain during pregnancy

  1. Benja Muktabhant1,*,
  2. Pisake Lumbiganon2,
  3. Chetta Ngamjarus3,
  4. Therese Dowswell4

Editorial Group: Cochrane Pregnancy and Childbirth Group

Published Online: 18 APR 2012

Assessed as up-to-date: 6 JAN 2012

DOI: 10.1002/14651858.CD007145.pub2


How to Cite

Muktabhant B, Lumbiganon P, Ngamjarus C, Dowswell T. Interventions for preventing excessive weight gain during pregnancy. Cochrane Database of Systematic Reviews 2012, Issue 4. Art. No.: CD007145. DOI: 10.1002/14651858.CD007145.pub2.

Author Information

  1. 1

    Khon Kaen University, Department of Nutrition, Khon Kaen, Thailand

  2. 2

    Khon Kaen University, Department of Obstetrics and Gynaecology, Faculty of Medicine, Khon Kaen, Thailand

  3. 3

    Faculty of Public Health, Khon Kaen University, Department of Biostatistics and Demography, Khon Kaen, Thailand

  4. 4

    The University of Liverpool, Cochrane Pregnancy and Childbirth Group, Department of Women's and Children's Health, Liverpool, UK

*Benja Muktabhant, Department of Nutrition, Khon Kaen University, Faculty of Public Health, 123 Friendship Highway, Khon Kaen, 40002, Thailand. bmuktabhant@yahoo.com.

Publication History

  1. Publication Status: New
  2. Published Online: 18 APR 2012

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Characteristics of included studies [ordered by study ID]
Asbee 2009

MethodsRandomised controlled trial, set in resident obstetric clinic in Charlotte, North Carolina, USA.


ParticipantsInclusion criteria: prenatal care established at 6-16 weeks of gestation, age 18-49 years, all prenatal care received at the Resident Obstetrics Clinic, English-speaking, Spanish-speaking, or both, and singleton pregnancy.

Exclusion criteria: BMI higher than 40, pre-existing diabetes, untreated thyroid disease, or hypertension requiring medication or other medical conditions that might affect body weight, delivery at institution other than Carolinas Medical Center Main, pregnancy ending in premature delivery (less than 37 weeks), and limited prenatal care (fewer than 4 visits).


InterventionsIntervention group (n = 57) received consistent program of dietary and lifestyle counselling. At the initial visit, participants met with a registered dietician to receive a standardised counselling session, including information on pregnancy-specific dietary and lifestyle choices. The counselling consisted of recommendations for a patient-focused caloric value divided in a 40% CHO, 30% protein, and 30% fat fashion. Patients were instructed to engage in moderate-intensity exercise at least 3 times per week and preferably 5 times per week. They also received information on the appropriate weight gain during pregnancy using the IOM guidelines. Each participant met with the dietician only at the time of enrolment. At each routine obstetrical appointment, the healthcare provider informed the participant whether her weight gain was at the appropriate level. If her weight gain was not within the IOM guidelines, the participant’s diet and exercise regimen were reviewed and she was advised on increasing or decreasing her intake and increasing or decreasing exercise.

Control group (n = 43) received routine prenatal care, including an initial physical examination and history, routine laboratory tests, and routine visits per American College of Obstetricians and Gynecologists standards. The only counselling on diet and exercise during pregnancy was that included in a standard prenatal booklet. The healthcare provider did not counsel the participant regarding any changes in diet or lifestyle.


OutcomesWeight gain, caesarean delivery, pre-eclampsia, shoulder dystocia.

Total weight gain was defined as weight just before delivery minus prepregnancy weight.


NotesAge (intervention, control): 26.7 ± 6.0, 26.4 ± 5.0.

Enrollment gestational age (intervention, control): 13.7 ± 3.6, 13.6 ±.2 weeks.

Prepregnancy BMI: 25.5 ± 6.0, 25.6 ± 5.1 kg/m².

BMI category, n (intervention, control)

  • underweight and normal weight (BMI < 26): 35, 25;
  • overweight (BMI 26-29.0): 10, 8;
  • obese (BMI > 29.0): 12, 10.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskRandomisation was performed using computer-generated random allocation.

Allocation concealment (selection bias)Low riskStudy allocation was concealed in numbered and sealed opaque envelopes.

Blinding (performance bias and detection bias)
All outcomes
Unclear riskNo information provided.

Incomplete outcome data (attrition bias)
All outcomes
Low riskNo loss to follow-up reported.

Trial authors stated that they had carried out an intention-to-treat analysis: data were analysed for participants according to their randomly-allocated group; all participants were included in the analysis.

Selective reporting (reporting bias)Low riskThe outcomes reported as in the published protocol.

Other biasLow riskDemographic data were similar. Age, prepregnancy weight, height and BMI were not different at baseline.

No other obvious bias.

Barakat 2011

MethodsRandomised controlled trial, set in Hospital de Fuen-labrada, Madrid, Spain.


Participants80 women randomised.

Inclusion criteria: healthy pregnant women (age, 23-38 years), had uncomplicated, singleton pregnancies.

Exclusion criteria: any type of absolute obstetric contraindication to aerobic exercise during pregnancy, which included other contraindications that the authors considered to have a relevant influence on maternal perception of health: significant heart disease, restrictive lung disease, incompetent cervix/cerclage, multiple gestation, risk of premature labour, pre-eclampsia/pregnancy-induced hypertension, thrombophlebitis, recent pulmonary embolism (last 5 years), acquired infectious disease, retarded intrauterine development, serious blood disease, and/or absence of prenatal care.


InterventionsIntervention group: (40 randomised) moderate physical activity, included a total of 35- to 45-minute weekly sessions 3 days each week from the start of the pregnancy (weeks 6-9) to the end of the 3rd trimester (weeks 38-39), an average of 85 training sessions, exercise intensity was light-to-moderate. Exercise was supervised by a fitness specialist and was in groups of 10-12 women.

Control group: (40 randomised) routine care.


OutcomesWeight gain, caesarean, birthweight < 4000 gm, birthweight > 4000 gm.


Notes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskRandomly assigned by use of a random number table.

Allocation concealment (selection bias)Unclear riskNot described.

Blinding (performance bias and detection bias)
All outcomes
Unclear riskNot mentioned. It would be difficult to blind women and staff to this type of intervention. It is not clear how lack of blinding would impact on the outcomes measured.

Incomplete outcome data (attrition bias)
All outcomes
Unclear risk80 women were randomised and 67 were analysed; 34 in the exercise group, 33 in the control group. Reason of discontinued were similar in both groups.

Selective reporting (reporting bias)Unclear riskAssessment from published study report.

Other biasUnclear riskNo between-group differences regarding potential confounding variables (such as occupational activities, standing, smoking habits, alcohol intake). Parity was not balanced between groups; the exercise group had a higher percentage of nulliparous women (76.5%) than the control group (36.4%).

Bechtel-Blackwell 2002

MethodsA prospective, quasi-experimental design, set in an adolescent prenatal clinic in USA.


ParticipantsAdolescent African American women aged 13-18 years were recruited during 1st trimester or early 2nd trimester.


InterventionsIntervention group (n = 22): the nutrition education intervention consisted of 3 20-minute group sessions that addressed nutritional needs specific to the women's stage of pregnancy.

Control group (n = 24): standard care for nutritional counselling.

Both groups received a nutrition assessment using a computer-assisted self-interview in 1st, 2nd, and 3rd trimesters.


OutcomesWeight gain, weight retention at 6 weeks' postpartum.


NotesThe data of weight gain were reported in terms of weight gain during the 1st, 2nd and 3rd trimester with no SDs reported.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskParticipants were randomly assigned to groups.

Allocation concealment (selection bias)High riskQuasi-randomisation.

Blinding (performance bias and detection bias)
All outcomes
Low riskGroup members would be unable to distinguish who was in the experimental group.

Incomplete outcome data (attrition bias)
All outcomes
High riskLoss to follow-up 23%; 26% in intervention group, 20% in control group.

Not provided information on reasons for loss to follow-up.

Selective reporting (reporting bias)Unclear riskCould not determine.

Other biasLow riskMaternal background characteristics revealed no statistically significant differences between groups.

Boileau 1968

MethodsRandomised controlled trial, place of study not stated.


ParticipantsPrivate patients in the 2nd trimester who were accumulating weight more rapidly and appeared to be excessively overweight at the beginning of pregnancy. Exclusion criteria were not reported.


InterventionsIntervention (n = 53): diethylpropion hydrochloride, 75 mg.

Control (n = 53): placebo.


OutcomesWeight change at each stage of gestation.


NotesNo SD for mean outcomes were reported.

Age (intervention, control): 26.3, 26.4.

Enrollment gestational age (intervention, control): 25, 25 weeks.

BMI before pregnancy (intervention, control): 25.3, 23.8 kg/m².


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNo information provided.

Allocation concealment (selection bias)Unclear riskNo information provided.

Blinding (performance bias and detection bias)
All outcomes
Low riskNeither the investigators nor the patients knew the content of the bottle.

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskCould not determine.

Selective reporting (reporting bias)Unclear riskCould not determine.

Other biasLow riskBaseline data showed the 2 groups were comparable.

Callaway 2010

MethodsRandomised controlled trial, set in a hospital in Brisbane, Australia.


Participants50 women randomised.

Inclusion criteria: obese pregnant women were recruited at 12 weeks’ gestation, aged 18-45, BMI ≥ 30  kg/m2,  pregnancy care at study hospital, willing and able to be randomised to an exercise intervention.

Exclusion criteria: non-English  speaking, contraindication or inability to exercise, medical or obstetric contraindication to exercise including haemodynamically significant heart disease, restrictive lung disease, incompetent cervix (cerclage), multiple  gestation, severe anaemia, chronic bronchitis, type 1 diabetes, orthopaedic limitations, poorly controlled seizure disorder, poorly controlled hyperthyroidism, or a heavy smoker.


InterventionsIntervention group: the intervention group received an individualised exercise program with an energy expenditure (EE) goal of 900 kcal/ week. Advice from physiotherapist and diaries for self-monitoring.

Control group: routine obstetric care.


OutcomesSelf-report of exercise (behaviour change).


Notes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskRandomisation was by a random number allocation technique conducted by a 3rd party.

Allocation concealment (selection bias)Unclear riskNot clear but external randomisation.

Blinding (performance bias and detection bias)
All outcomes
High riskNo blinding.The impact of the lack of blinding was not clear. The use of self-monitoring diaries by the intervention group may have introduced recall bias.

Incomplete outcome data (attrition bias)
All outcomes
High riskRandomised 50 women, at 36 weeks 36 were followed up (30% attrition).

Selective reporting (reporting bias)Unclear riskAssessment from published study report and on-line supplement.

Other biasUnclear riskThere were no statistically significant differences between the intervention and control groups in any baseline variable. Different monitoring techniques in the 2 groups (diaries in the intervention group) may have led to recall bias.

Clapp 2002

MethodsA prospective randomised design.


Participants20 healthy women with uncomplicated pregnancy.


InterventionsThe participants were enrolled prior to pregnancy and placed on a regular regimen of supervised exercise and began a weight maintaining diet (low glycaemic sources of CHO). At 8 weeks' gestation, they were randomised to either diet containing low glycaemic CHO sources(n = 10) (aboriginal CHO diet) or high glycaemic CHO sources (n = 10) (cafeteria CHO diet). All continued the same exercise regimen throughout pregnancy.


OutcomesWeight gain.

Total weight gain was defined as weight at delivery minus prepregnancy weight.


NotesDuring pregnancy, all women were allowed to increase caloric intake according to appetite with advancing gestation.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNot described.

Allocation concealment (selection bias)Unclear riskNo information provided.

Blinding (performance bias and detection bias)
All outcomes
Unclear riskNo information provided.

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskUnspecified loss to follow-up.

Selective reporting (reporting bias)Unclear riskNo information provided.

Other biasUnclear riskNo information provided.

Clapp 2002a

MethodsRandomised controlled trial, set in Case Western Reserve University at metro health medical centre, USA.


ParticipantsInclusion criteria: 80 healthy, regularly exercising (≥ 3 times/week), non-substance-abusing women were enrolled before pregnancy.

After conception (which occurred within 4 months in all cases) and ultrasonic confirmation of a viable singleton pregnancy, these women were assigned in week 8 of gestation to the exercise regimens.

Exclusion criteria: not stated.

Number of participants: 75 women enrolled and complete the protocol; 26 in Lo-Hi group, 24 in Mod-Mod group, 25 in Hi-Lo group.


InterventionsThere were 3 study groups:

group 1: low-high exercise (n = 26): exercise 20 minutes 5 days a week through to week 20, gradually increasing to 60 minutes 5 days a week by week 24 and maintaining that regimen until delivery (Lo-Hi).

group 2: moderate-moderate exercise (n = 24): exercise 40 minutes 5 days a week from week 8 until delivery (Mod-Mod).

group 3: high-low exercise (n = 25): exercise 60 minutes 5 days a week through to week 20, gradually decreasing to 20 minutes 5 days a week by week 24 and maintaining that regimen until delivery (Hi-Lo).


OutcomesWeight gain.


NotesAge 31 ± 1, 30 ± 1, 32 ± 1 in Lo-Hi, Mo-Mo, Hi-Lo.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskWomen were randomly assigned.

Allocation concealment (selection bias)Unclear riskWomen were randomly assigned by envelope but it was not stated whether envelopes were sequentially numbered, opaque and sealed.  

Blinding (performance bias and detection bias)
All outcomes
High riskA member of the study team carried out morphometric assessment of placenta and infant at the time of birth.                                                                                       

Incomplete outcome data (attrition bias)
All outcomes
Low riskLoss to follow-up 6.25%.                           

Selective reporting (reporting bias)Unclear riskCould not determine.

Other biasLow riskBaseline data were similar.

Guelinckx 2010

MethodsRandomised controlled trial, set in the prenatal clinic, University Hospital of Leuven, Belgium.


ParticipantsInclusion criteria: obese (BMI > 29.0 according to IOM criteria), white women consecutively attending the prenatal clinic before 15 week of gestation.

Exclusion criteria: preexisting diabetes or developing GDM, multiple pregnancy, recruitment after 15 week of gestational age, premature labour (delivery before 37 week of gestation), primary need for nutritional advice in case of a metabolic disorder, kidney problems, Crohn's disease, allergic conditions, and inadequate knowledge of the Dutch language.


Interventions2 intervention groups: the passive group (n = 37): received a brochure during the 1st prenatal consultation. This brochure was specifically designed for the study and provided advice on nutrition and on physical activity and tips to limit pregnancy-related weight gain. The active group (n = 42): received the same brochure and women were actively counselled by a trained nutritionist in 3 group sessions. A maximum of 5 women were brought together in these 1-hour sessions, which were scheduled at 15, 20, and 32 weeks of pregnancy. The sessions provided subjects with recommendations on a balanced, healthy diet, based on the Official National Dietary Recommendations (9–11% of the energy should come from proteins, 30–35% from fat, and 50–55% from CHOs).

Control group (n = 43): received routine prenatal care.

(Energy intake was not restricted in any group.)


OutcomesExcessive weight gain (weight gain more than the upper limit recommendation for overweight women; > 11.2 kg).

Gestational weight gain.

Obstetrical and neonatal outcome: pre-eclampsia, induction of labour, caesarean section, birthweight > 4000 gm.

Average energy intake.

Weight gain was defined as weight at birth minus prepregnancy weight.

Total physical activity score at 3rd trimester.

For analysis 3.10 and 4.10 a physical activity score was calculated by using a questionnaire including a total 16 questions classified into 3 domains: work, sports, and non-sports leisure-time activities, scored on a 5-point scale, ranging from “never”, “seldom”, “sometimes”, “very often”, to “always”.  A total score for physical activity from a minimum of 3 to a maximum of 15 was obtained. A higher score indicated more activity.


NotesAge 29.4 ± 4.4, 28.7 ± 4.0, 28.0 ± 3.6 years for control group, passive group, active group.

Enrollment gestational age: 10.2 ± 2.4, 10.2 ± 2.6, 9.3 ± 2.8 weeks for control group, passive group, active group.

Prepregnancy BMI: 33.5 ± 3.9, 33.4 ± 3.07, 34.1 ±4 .5 kg/m2 for control group, passive group, active group.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNo information provided.

Allocation concealment (selection bias)Low riskPatients were randomly assigned by using block randomisation.

Blinding (performance bias and detection bias)
All outcomes
Unclear riskNo information provided.

Incomplete outcome data (attrition bias)
All outcomes
Low riskLoss to follow-up 9.7%.

Reasons for excluding the participants from each group were similar.

Selective reporting (reporting bias)Unclear riskCould not determined.

Other biasLow riskBaseline characteristics of participants were similar between intervention and control groups.

Huang 2011

MethodsRandomised controlled trial; 3 groups intervention design; 2 experimental groups (from pregnancy to 6 months postpartum (EP) and from birth to 6 months postpartum (EPP). The group receiving the intervention in the postnatal period only is not included in our analysis) and 1 comparison group.


ParticipantsFrom January to June 2006, pregnant women were recruited from the obstetric clinics of a hospital in Taiwan. (160 women randomised.)

Inclusion criteria:16 gestational weeks, age 18 years or older, no cognitive impairment or psychiatric illness, ability to speak and read Chinese, not participating in another study, and intention to give birth at the study site.


InterventionsIntervention group: (80 participants).The educational intervention began at 16 gestational weeks (baseline) and to 6 months postpartum. The intervention was delivered at regularly scheduled clinic visits by nurses with training in nutrition and physical fitness. The nurse discussed with each participant how to design an individualised diet and physical activity plan. The intervention consisted of 6 1-to-1 counselling sessions: 1 primary session (about 30–40 minutes) at the 16-week gestation visit, and 5 1-to-1 booster sessions (at 28 gestational weeks, 36–38 gestational weeks, before hospital discharge after a 3–7-day stay, 6 weeks' postpartum and 3 months postpartum). After each clinic visit, women in the experimental groups were sent a personalised graph of their weight changes. At the 1st session, the experimental groups also received a researcher-prepared brochure that provided detailed information on weight management goals during pregnancy and postpartum.

Control group: (80 participants) routine care, provided once each trimester which health education on nutrition and exercise during pregnancy.


OutcomesGestational weight gain, weight retention at 6 months postpartum, health-promoting behaviour; physical activity.

For analysis 1.9.1 physical activity measurement was a part of the health-promoting lifestyle profile composed of 50-item scale uses a 4-point response format (range = 50–200) to measure the frequency of engaging in activities related to self-actualisation, nutrition, physical activity,interpersonal support, health responsibility and stress management.


Notes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskUsing a table of random numbers.

Allocation concealment (selection bias)Unclear riskNot stated.

Blinding (performance bias and detection bias)
All outcomes
Unclear riskThe research assistant collecting outcome data was reported to be blind to the group assignments.

Incomplete outcome data (attrition bias)
All outcomes
Unclear risk80 women in each group were randomised, 61 and 64 of intervention and control group were analysed (78% followed up).

Selective reporting (reporting bias)Unclear riskAssessment from published study report.

Other biasLow riskNo notable baseline differences were found between groups.

Hui 2006

MethodsRandomised controlled trial, set in a community nurse-managed centre and the Manitoba Clinic, both in urban Winnipeg, Manitoba, Canada.


ParticipantsInclusion criteria: women < 26 weeks pregnant with no pre-existing diabetes were recruited on a voluntary basis. 

Exclusion criteria: pregnant women who had medical obstetric, skeletal or muscular disorders that could contraindicate physical exercise during pregnancy.


InterventionsIntervention (n = 24): additional intervention: lifestyle intervention including exercise intervention and dietary intervention.

Exercise intervention: participants were instructed in group-session exercises and in home-based exercise. Weekly group session included floor aerobics, stretching and strength exercises, 3-5 times/week for 30-45 minutes per session, video provided to participants to assist with home-based exercise.

Nutrition intervention: computer-assisted food choice map interview, dieticians provided a personalised plan for participants.

Control (n = 21): standard care group received an information package on diet and physical activity for a healthy pregnancy.


OutcomesExcessive weight gain, weight gain, cesarean section, infant birthweight > 4000 gm, and physical activity at end of study.

Weight gain was defined as weight at birth (from medical chart) minus prepregnancy weight.

For analysis 1.9.1 physical activity was defined as recreational physical activity which was measured by using the PARmed-X for Pregnancy form based on Health Canada recommendations. Low levels (physical activity = 0) are defined as either no physical activity or activity < 1 to 2 times per week and for < 20 min per session; moderate levels (physical activity = 1) are defined as activity 1 to 2 times per week and for > 20 min per session or > 2 times per week and for < 20 min per session; high level (physical activity = 2) are defined as activity > 2 times per week and for > 20 min per session.


NotesAge (intervention, control): 26.2 ± 5.7, 26.2 ± 5.4.

Prepregnancy BMI (intervention, control): 25 ± 6.3, 23.4 ± 3.9 kg/m².

Excessive weight gain was assessed based on prepregnant BMI.

  • BMI < 20 kg/m², weight gain during pregnancy 12.5 -18 kg.
  • BMI 20-27 kg/m², upper limit of weight gain 16 kg.
  • BMI > 27 kg/m², upper limit of weight gain 11.5 kg.


(Canadian guidelines for healthy weights.)

Majority of participants (89%) were from low-income families or low-middle income families.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskParticipants were enrolled and randomised into additional intervention and standard care groups.

Allocation concealment (selection bias)Unclear riskNo information provided.

Blinding (performance bias and detection bias)
All outcomes
Unclear riskNo information provided.

Incomplete outcome data (attrition bias)
All outcomes
High risk52 enrolled, 45 completed. Loss = 7/52*100 = 13.5%. 

7 pregnant women dropped out due to school or work commitments.

The participants who dropped out were significantly younger and had lower incomes than those who completed the program (P < 0.01).

Selective reporting (reporting bias)Unclear riskCould not determine.

Other biasLow riskNo significant differences were found in age, prepregnancy BMI, and family income between additional intervention and standard care groups.

Jackson 2011

MethodsRandomised controlled trial, set in 5 prenatal care practices in the San Francisco Bay Area, USA, including 3 public hospitals, 2 academic practices, and a community hospital. 2006-2007.


Participants327 women randomised.

Inclusion criteria: English-speaking women 18 years or older and less than 26 weeks of gestation.

Exclusion criteria: women who report smoking, alcohol use, drug use, or partner violence.


InterventionsIntervention group: (163 randomised) The Video Doctor: an interactive computer program including in-depth behavioural risk assessments and tailored counselling messages, and producing printed output for both the patient and clinician. An actor-portrayed Video Doctor appears and offers education on exercise, nutrition and weight gain based on principles of Motivational Interviewing. Dietary counselling focused on increasing intake of fruits and vegetables and whole grains, increasing healthful versus unhealthful fats and decreasing sugary foods. The Video Doctor emphasised dietary and exercise behaviour changes over weight gain. The Video Doctor programme required 10–15 minutes to complete. After 4 weeks, participants received a brief ‘‘booster’’ Video Doctor counselling.

Control group: (164 randomised) usual care. The usual care group did not interact with the Video Doctor and the program did not produce a Cueing Sheet or Educational Worksheet. Behavioural counselling for the usual care group was determined by the clinician.


OutcomesSelf-reported servings per day or week of healthful foods (e.g. fruits and vegetables) and unhealthful foods (e.g. sweets), and exercise duration and frequency, and weight gain above the IOM guidelines.


Notes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskRandomisation by computer.

Allocation concealment (selection bias)Low riskRandomisation by computer (interactive computer programme intervention).

Blinding (performance bias and detection bias)
All outcomes
Unclear riskParticipants would not be blind to the intervention. It was not stated that staff or outcome assessors were blinded.

Incomplete outcome data (attrition bias)
All outcomes
Low risk6 women were excluded after randomisation: 3 due to insufficient English, 1 because of inaccurate gestational age, and 2 withdrew during the baseline assessment leaving 158 in the Video Doctor group and 163 in the usual care group. Intention-to-treat analysis was performed for primary outcome (weight gain) for other outcomes 327 were randomised and 287 (88%) completed follow-up.

Selective reporting (reporting bias)Unclear riskAssessment from published study report.

Other biasUnclear riskThere were no significant differences between the control and Video Doctor groups for any of the demographic variables listed except education. Results for weight gain were not fully reported by randomisation group. Results for  mean weight gain of each group were reported without SDs.

Jeffries 2009

MethodsRandomised controlled trial, set in a tertiary obstetric hospital in Melbourne, Australia.


ParticipantsInclusion criteria: pregnant women at < 14 weeks' gestation.

Exclusion criteria: age < 18 or > 45 years, type 1 or type 2 diabetes mellitus, multiple pregnancy, or non-English speaking.


InterventionsIntervention (n = 125): women allocated to the intervention group were given a personalised weight measurement card, advised of their optimal gestational weight gain (based on their BMI at the time of recruitment and the United States IOM guidelines, and instructed to record their weight at 16, 20, 24, 28, 30, 32 and 34 weeks' gestation.

Control (n = 111): not given instructions about regular weight measurement.


OutcomesWeight gain above IOM guideline, mean weight gain from recruitment to follow-up at 36 weeks' gestation.

Small-for-gestational age (< 10th centile), large-for-gestational age (> 90th centile), preterm (< 37 weeks), instrumental delivery, caesarean delivery, pre-eclampsias, neonatal hypoglycaemia, shoulder dystocia.

Weight gain was weight difference between weight at about 36 weeks' gestation and weight at 1st antenatal appointment.


NotesGestation age at recruitment (intervention, control): 11.6, 11.4 weeks.

BMI category, n (intervention, control):

  • underweight (BMI ≤ 19.8): 5, 5;
  • normal (BMI > 19.8, ≤ 26.0): 75, 67;
  • overweight (BMI > 26, ≤ 29.0): 20, 18;
  • obese (BMI > 29.0): 25, 21.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskUsing computer random number generation.

Allocation concealment (selection bias)Low riskUsing opaque, sequentially numbered envelopes.

Blinding (performance bias and detection bias)
All outcomes
Low riskAll participants were blinded to the purpose of the study.

Incomplete outcome data (attrition bias)
All outcomes
Low riskLoss to follow-up, 23/148 in intervention group, 27/138 in control group.

Similar reason of loss to follow-up in intervention and control groups.

Selective reporting (reporting bias)Low riskThe outcomes reported as in the published protocol.

Other biasLow riskBaseline characteristics were similar.

Korpi-Hyovalti 2011

MethodsRandomised controlled trial, set in 2 hospitals in rural municipalities (Kauha-joki and Lapua) in Finland.


Participants60 women randomised.

Inclusion criteria: women at high risk of gestational diabetes: women had 1 or more risk factors (BMI > 25 kg/m2, previous history of GDM or birth of child > 4.5 kg, age > 40 years, family history of diabetes or the venous plasma glucose concentration after 12 hours fasting in the morning was 4.8-5.5 mmol/L and 2-hour OGTT plasma glucose < 7.8 mmol/L.

Exclusion criteria: women who were diagnosed as having GDM in this study and women who had risk factors for GDM or whose fasting venous plasma glucose was 4.8-5.5 mmol/L but who for personal or professional reasons did not wish to participate in the trial.


InterventionsIntervention group: (n = 30) a lifestyle intervention; included diet counselling and exercise counselling. Dietary advice tailored to each subject individually on 6 occasions. Women were encouraged to eat a diet rich in vegetables, berries and fruits, and to use low-fat. Moderate-intensity physical exercise during pregnancy was encouraged, 6 sessions for exercise counselling.

Control group: close follow-up group (n = 30). All women were given general information on diet and physical activity to decrease the risk of GDM during pregnancy as part of routine care.


OutcomesWeight gain.


Notes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskWomen were randomly assigned to the lifestyle intervention group or to the close follow-up group by the study physician in the Central Hospital with the use of a computed randomisation list.

Allocation concealment (selection bias)Unclear riskNot stated.

Blinding (performance bias and detection bias)
All outcomes
Unclear riskWomen would be aware of group assignment although it was stated that the nurses scheduling study visits did not have access to the randomisation list. It is not clear what impact the lack of blinding would have on the outcomes measured.

Incomplete outcome data (attrition bias)
All outcomes
Unclear risk60 women were randomised, 54 were followed up.

Selective reporting (reporting bias)Unclear riskAssessment from published study report.

Other biasUnclear riskThere were no statistically significant differences in baseline measures between the lifestyle intervention and the close follow-up groups although women in the intervention group had slightly higher prepregnancy weight (mean 76.6 compared with 69.6 in controls.

Laitinen 2009

MethodsRandomised controlled trial, set in maternal welfare clinics in the city of Turku and neighbouring areas in south-west Finland.


ParticipantsWomen were eligible for participation if they were less than 17 weeks’ gestation and had no metabolic or chronic diseases such as diabetes.

Participants were Caucasian.


InterventionsAt 1st trimester 256 pregnant women were allocated to 3 groups: modification of dietary intake according to current recommendations with probiotics or placebo and a control group receiving placebo only.

  1. Control group, (placebo) (n = 85).
  2. Intervention group 1 (n = 86) (diet counselling and placebo).
  3. Intervention group 2 (n = 85) (diet counselling and probiotics), probiotic capsules containing Lactobacillus rhamnosus GG and Bifidobacterium lactis Bb12.


Dietary counselling given by a dietitian at each study visit aimed to modify dietary intake to conform with that currently recommended, particular attention being paid to the quality of dietary fat.

Study visits took place 3 times during pregnancy at 13·9 (SD 1·6), 23·8 (SD 1·4) and 33·9 (SD 1·4) weeks of gestation and at 1, 6 and 12 months postpartum.


OutcomesWeight gain, energy intake, dietary fibre intake at 3rd trimester of pregnancy.

Weight gain was calculated by subtracting self-reported prepregnancy weight from that recorded at a prenatal visit or at hospital within 1 week before delivery.


NotesAge (intervention 1, intervention 2, control): 30.1 ± 5.2, 29.7 ± 4.1, 30.2 ± 5.0.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskSubjects were randomly assigned to 3 study groups according to computer-generated block randomisation.

Allocation concealment (selection bias)Low riskUsing sealed envelopes. At the 1st study visit the envelopes were opened. The random allocation sequence was thus concealed until interventions were assigned.

Blinding (performance bias and detection bias)
All outcomes
Low riskIntervention groups took place in a double-blind manner, while the control group received placebo in single-blind manner.

Incomplete outcome data (attrition bias)
All outcomes
Low riskNo loss to follow-up (to delivery).

Selective reporting (reporting bias)Low riskThe outcomes reported as in the published protocol.

Other biasLow riskNo other bias apparent.

Luoto 2011

MethodsCluster-randomised controlled trial, set in primary healthcare centres in 14 municipalities in Pirkanmaa region in south-western Finland.


ParticipantsRecruitment 2007-8.

Inclusion criteria: Pregnant women at 8–12 weeks' gestation at high risk of developing gestational diabetes;  BMI ≥ 25 kg/m² based on measured height and self-reported prepregnancy weight; GDM or any signs of glucose intolerance or newborn’s macrosomia (≥ 4500 gm) in any earlier pregnancy; type 1 or 2 diabetes in 1st- or 2nd-degree relatives; or age ≥ 40 years.

Exclusion criteria: at least 1 of the 3 baseline (8–12 weeks' gestation) OGTT measurements was abnormal (fasting blood glucose ≥ 5.3 mmol/L, 10.0 mmol/L at 1 hr, and 8.6 mmol/L at 2 hr); prepregnancy type 1 or 2 diabetes; inability to speak Finnish; age <18 yr; multiple pregnancy; physical restriction preventing physical activity; substance abuse; treatment or clinical history of psychiatric illness.


InterventionsIntervention group: (7 municipalities) Individual counselling on physical activity and diet and weight gain. At the 1st visit the recommendations for gestational weight gain were discussed and an appropriate weight gain graph was selected to guide the participant in monitoring her weight gain. The primary physical activity counselling was implemented at 8–12 weeks' gestation and the primary dietary counselling session at 16–18 weeks' gestation. Physical activity counselling was enhanced at 4, and diet counselling at 3 subsequent visits.

Control group: (7 municipalities) usual care group received no counselling beyond usual care, which included some dietary counselling (partly on different topics) and follow-up of gestational weight, but little physical activity counselling.


OutcomesIncidence of GDM as assessed by OGTT (maternal outcome) and newborns’ birthweight adjusted for gestational age, maternal weight gain and the need for insulin treatment during pregnancy, changes in physical activity and diet (intake of total fat, saturated and polyunsaturated fatty acids, saccharose, and fibre.


Notes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskThe unit of randomisation was municipality. In the randomisation process, participating municipalities were 1st pair-wise matched. 14 municipalities were then randomised by computer.

Allocation concealment (selection bias)Low riskCluster-randomised trial with computer randomisation.

Blinding (performance bias and detection bias)
All outcomes
Unclear riskThe impact of lack of blinding in this trial is unclear.

Women would be aware of intervention and so would staff. Women in the intervention group were provided with notebooks to record diet and activity, women in the control group were not; this may have affected recall and may have introduced bias. It was not clear whether staff collecting outcome data were blind to group assignment.

Incomplete outcome data (attrition bias)
All outcomes
High risk14 clusters were randomised and all were included in the analysis. 343 women in the intervention and 297 in the usual care group agreed to participate in the trial. However, 81 (23.6%) of the participants in intervention group and 93 (31.3%) of the participants in the usual care group had an abnormal OGTT result at baseline and were thus excluded. The final number of participants in the analyses was 219 (89.0% of participants receiving allocated intervention) in the intervention group and 180 (91.8% of participants receiving allocated intervention) in the usual care group. However about 40%of eligible participants of each group were followed up.

Selective reporting (reporting bias)Unclear riskAssessment from published study reports.

Other biasUnclear riskBaseline characteristics of each group were similar, except there were women in the intervention group with high education than in the usual care group. There was adjustment of data for clustering and various cluster, clinic and individual level differences at baseline.

Magee 1990

MethodsRandomised controlled trial, set in prenatal care at the University of Washington Obstetrics Clinics.


ParticipantsPregnant women with obesity (prepregnancy weight > 120% of ideal body weight) and diagnosed with gestational diabetes, recruited at 28 weeks' gestation.


InterventionsAll patients were hospitalised for 2-week duration in the metabolic ward.

Intervention; calorie-restricted (n = 7): during the 1st week, the women consumed normal diet with 2400 kcal/day; 50% CHO, 30% fat and 20% protein with 11 gm of total dietary fibre per 500 kcal. During the 2nd week, the women were placed on 1200 kcal/day diet. This reduction was accomplished by decreasing portion sizes without changing other features of diet.

Control (n = 5): during the 1st week, the patients consumed identical diet as the intervention group; 2400 kcal/day, and continued on the same diet (2400 kcal/day) during the 2nd week.


OutcomesMetabolic indices: fasting plasma glucose, OGTT, insulin, triglyceride, free fatty acids, glycerol, ß-hydroxybutyrate, and urine ketones.

We have not included outcome data from this hospital inpatient study in the analyses in the review.


NotesAge (calorie-restricted, control): 30 ± 4, 36 ± 5 years.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNo information provided.

Allocation concealment (selection bias)Unclear riskNo information provided.

Blinding (performance bias and detection bias)
All outcomes
Unclear riskNo information provided.

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskNo information provided.

Selective reporting (reporting bias)Unclear riskCould not determine.

Other biasUnclear riskNo information provided.

Moses 2006

MethodsQuasi-randomised controlled trial, set in antenatal clinic at Wollongong Hospital, Wollongong, NSW, Australia.


ParticipantsInclusion criteria: healthy, pregnant women from the antenatal clinic at Wollongong Hospital and from 2 obstetricians in private practice. They were aged 21– 40 years, had a singleton pregnancy, were between 12 and 16 weeks' gestation, were nonsmokers, and consumed no more than 1 alcoholic drink each day.

Exclusion criteria: any problem associated with glucose metabolism or insulin resistance or that interfered with the ability of the study participant to follow dietary instructions.


InterventionsParticipants were randomised to a low glycaemic diet or high glycaemic diet.

Low glycaemic diet (n = 32): seen by dietitian 5 times during pregnancy, received dietary recommendation for low GI diet with 33% fat, 55% CHO. The low GI diet was based on verified low-GI foods, including pasta and brand-name breads and breakfast cereals with a high fibre content.

High glycaemic diet (n = 30): also seen by dietitian 5 times during pregnancy, received dietary recommendation for moderate-to-high GI diet (high fibre, low sugar) with 33% fat, 55% CHO.


OutcomesWeight gain (from 12 weeks to 36 weeks), large-for-gestational age (> 90th centile for birthweight), small-for-gestational age (< 10th centile for birthweight).


NotesAge (low GI, high GI): 30.1 ± 0.7, 29.6 ± 0.7.

BMI at baseline (low GI, high GI): 24.4 ± 0.7, 26.6 ± 0.9 kg/m².

The baseline visit was between 12-16 weeks' gestation.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)High riskAlternation.

Allocation concealment (selection bias)High riskAlternate allocation to study groups.

Blinding (performance bias and detection bias)
All outcomes
Unclear riskNo information provided.

Incomplete outcome data (attrition bias)
All outcomes
Low riskLoss of participants to follow-up: In the low–GI diet group, 2 women withdrew due to being unwilling to follow the diet and 1 delivered before the final visit. In high-GI diet group, 1 woman was unwilling to follow the diet, 1 lost to follow-up, and 3 miscarriages.

Intention-to-treat analysis: data were analysed for participants according to their randomly-allocated group, not all original participants were included in the analysis.

Selective reporting (reporting bias)Unclear riskCould not determine.

Other biasLow riskBaseline characteristics were similar.

Moses 2009

MethodsRandomised controlled trial, set in the city of Wollongong, New South Wales, Australia.


ParticipantsInclusion criteria: pregnant women, age 18–40 years (inclusive), singleton pregnancy, no previous GDM, nonsmoker, diagnosis of GDM and seen for the 1st dietary visit between 28 and 32 weeks of gestation, and ability to follow the protocol requirements.

Exclusion criteria: any condition or medication that could affect glucose levels and unwillingness to follow the prescribed diet.


Interventions63 women were randomly assigned to receive 1 of 2 different diets, low–GI diet (n = 31) or higher–GI diet (n = 32). Both diets were compatible with the recommended nutritional intake in pregnancy. The CHO intake was designed to achieve a minimum of 175 gm/day with only the recommended choice of CHO foods varying. The dietary advice by dietitian was individualised with specific mention of the energy and nutrient balance to achieve normal weight gain during the 3rd trimester.

The low–glycaemic diet: based on previously verified low–GI food, including pasta, grain breads, and unprocessed breakfast cereals with a high fibre content. Women were specifically asked to avoid consuming white bread, processed commercial breakfast cereals, potatoes, and some rice varieties.

The higher–glycaemic diet: a diet with a high-fibre and low-sugar content, with no specific mention of the GI. Potatoes, whole wheat bread, and specific high-fibre, moderate-to-high–GI breakfast cereals were recommended.


OutcomesInduction of labour, method of delivery, large-for-gestational-age baby (> 90th centile), small-for-gestational-age baby (< 10th centile).


NotesAge (LGI, HGI): 30.8 + 0.7, 31.3 + 0.8.

Gestational age at entry to study (LGI, HGI): 30.3 + 0.2 weeks, LGI 29.9 + 0.2 weeks.

BMI at enrolment (LGI, HGI): 32.0, 32.8 kg/m².


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskWomen were randomly assigned using permuted blocks of unequal size with the list generated using STATA (version 7.0).

Allocation concealment (selection bias)Unclear riskNot stated.

Blinding (performance bias and detection bias)
All outcomes
Low riskThe physician caring for the patients was blinded.

Study dietitians were not blinded to dietary assignment but were aware of the need for impartiality and equivalent treatment.

Participants were impossible to blind to the GI concept, as it is widely known and discussed in the lay press.

Incomplete outcome data (attrition bias)
All outcomes
Low riskNo drop-out apparent.

Selective reporting (reporting bias)Unclear riskCould not determine.

Other biasLow riskThere were no significant differences in the baseline characteristics of the 2 groups.

Phelan 2011

MethodsRandomised controlled trial, 2 arms with individual randomisation (stratified by prepregnancy weight, set in 6 obstetric offices in Providence, Rhode Island, USA  from 2006 to 2008.


Participants401 women randomised.

Inclusion criteria: gestational age between 10 and 16 weeks, BMI between 19.8 and 40, nonsmoking , adults (aged > 18 yr), fluency in English, access to a telephone, and a singleton pregnancy.

Exclusion criteria: major health or psychiatric diseases, weight loss during pregnancy, or a history of ≥ 3 miscarriages.


InterventionsIntervention group: standard care plus a behavioural lifestyle intervention. The Fit for Delivery intervention included a face-to-face visit with an interventionist at the onset of treatment who discussed appropriate weight gains during pregnancy, physical activity (30 min of walking most days of the week), and calorie goals (20 kcal/kg); emphasis was placed on decreasing high fat foods, increasing physical activity, and daily self-monitoring of eating, exercise, and weight. Body-weight scales, food records, and pedometers were provided to promote adherence to daily self-monitoring. Automated postcards that prompted healthy eating and exercise habits were mailed weekly. In addition, after each clinic visit, women were sent personalised graphs of their weight gains with feedback. All women in the intervention received 3 brief (i.e., 10–15 min) supportive phone calls from the dietitian during the intervention. Women who were over or under weight-gain guidelines during any 1 month interval received additional brief, supportive phone calls (2 calls/mo) that provided structured meal plans, and specific goals until weight gains returned to appropriate amounts.

Control group: routine care. Women received standard nutrition counselling provided by physicians, nurses, nutritionists, and counsellors. As part of routine care women were weighed by nurses at each clinical visit; weight graphs were not provided.


OutcomesExcessive weight gain, low weight gain, preterm birth, pre-eclampsia or eclampsia, caesarean delivery rate, high birthweight, low birthweight, maternal weight retention.


Notes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskRandomisation was computer-generated in randomly varying block sizes and stratified by clinic and BMI category.

Allocation concealment (selection bias)Low riskAllocation was concealed in opaque envelopes prepared by the study statistician.

Blinding (performance bias and detection bias)
All outcomes
Unclear riskUnblinded study research coordinator enrolled and randomly assigned participants into groups. In the abstract it was stated that outcome assessors were blinded.

Incomplete outcome data (attrition bias)
All outcomes
Low riskLost to follow-up 34 in the standard care group, 36 in the intervention group. Exclusions: 18  in the standard care group, 25 in the intervention group.

401 participants were randomly assigned into the intervention (n = 201) and control groups ( n = 200), included in 6 month postpartum analysis; 182 control, 176 intervention.

ITT analysis was performed assuming that those lost to follow-up were treatment failures. It was reported that this revealed almost identical results as for those completing the study (data not shown).

Selective reporting (reporting bias)Unclear riskAssessment from published study report.

Other biasUnclear riskThe 2 study groups did not significantly differ on key baseline measures (sample stratified).

Polley 2002

MethodsRandomised controlled trial, set in an obstetric clinic for low-income women at a hospital in Pittsburgh, PA, USA.


ParticipantsInclusion criteria: pregnant women before 20 weeks of gestation. (Subjects were recruited in to 4 cells; normal and overweight, black and white.) 

Exclusion criteria: underweight women, younger than 18 years, 1st prenatal visit > 12 weeks' gestation, high-risk pregnancy (i.e.. drug abuse, chronic health problems, previous complications during pregnancy, current multiple gestation).


InterventionsIntervention (n = 57): the intervention was provided at regular scheduled clinic visits by staff with training in nutrition or clinical psychology. Education about weight gain, healthy eating, and exercise and individual graphs of their weight gain.

Shortly after recruitment, written and oral information were given in the following area: appropriate weight gain, exercise, healthy eating.Newsletters prompting healthy eating and exercise habits were mailed bi-weekly. After each clinic visit, women were sent a personalised graph of their weight gain.

Those exceeding weight gain goals were given additional individualised nutrition and behavioural counselling using the format listed; a stepped care approach.

Control (n = 53): usual care: standard nutrition counselling provided by the physicians, nurses, nutritionists and WIC counsellors. This counselling emphasised a well-balanced dietary intake and advice to take a multivitamin/iron supplement.


OutcomesExcessive weight gain, total weight gain, low weight gain.

Low birthweight infants, macrosomia infants, preterm delivery, caesarean delivery, pre-eclampsia, weight retention at 4 weeks' postpartum.

Total weight gain was based on self-reported prepregnancy weight and weight at last clinic visit prior to delivery.


NotesExcessive weight gain categorised as above the IOM recommendations.

Low weight gain categorised as below the IOM recommendations.

IOM recommends a weight gain of 6.8-11.3 kg for overweight women (BMI of 26-29) and a weight gain of 6.8 kg (with no specified upper limit) for obese women (BMI > 29).

Age of participants 25.5 ± 4.8.

Gestational age at recruitment (intervention, control): 14.7 ± 3.1 weeks.

BMI category, n (intervention, control):

  • normal weight (BMI19.8-26): 30, 31;
  • overweight (BMI > 26): 27, 22.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskWomen were randomly assigned to the standard care control group or to the intervention.

Allocation concealment (selection bias)Unclear riskNo information provided.

Blinding (performance bias and detection bias)
All outcomes
Unclear riskNo information provided.

Incomplete outcome data (attrition bias)
All outcomes
Low riskUsing intention-to-treat approach.

Loss to follow-up < 10%.

Selective reporting (reporting bias)Unclear riskCould not determine.

Other biasHigh riskRefusal rates were higher among black women (28/74 refused) than among white (16/90 refused), and higher in overweight black women than in any of the other 3 weight-by-race categories.

Quinlivan 2011

MethodsRandomised controlled trial, set in the maternity service of a public general hospital serving a socioeconomically disadvantaged area in Melbourne, Australia.


Participants132 randomised.

Inclusion criteria: pregnant with a fetus with no known anomalies, spoke English, did not intend to relinquish their infant, did not have a multiple gestation, were able to attend hospital for antenatal care and were overweight (BMI 25–29. 9) or obese (BMI > 29 .9).

Exclusion criteria: not described.


InterventionsIntervention group: a 4-step multidisciplinary protocol of antenatal care which had the following 4 criteria : (i) continuity of care provider; (ii) weighing on arrival; (iii) brief dietary intervention by a food technologist at every antenatal visit; and (iv) psychological assessment. Women attended special study clinics.

Control group: routine care (with access to high-risk clinics if medically indicated).


OutcomesWeight gain, preterm delivery.


Notes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskRandomisation to the intervention or control groups occurred using computer-generated sequence.

Allocation concealment (selection bias)Low riskNumbered sealed opaque envelopes, stratified by category (overweight or obese;16), which were only opened by the midwife after each woman’s enrolment was completed.

Blinding (performance bias and detection bias)
All outcomes
Unclear riskOutcome data for mother and infant were audited by a nurse independent of clinical care pathways and blinded to randomisation status.

Incomplete outcome data (attrition bias)
All outcomes
Low risk132 randomised, 124 analysed (8 excluded from analysis (4 of each group).

Selective reporting (reporting bias)Unclear riskAssessment from published study report.

Other biasUnclear riskThere were no significant differences in terms of antenatal, demographic and health behaviour variables between intervention and control groups.

Women in the intervention group attended special study clinics; these clinics may have been different from standard clinics in more ways than the intended study interventions (although it was stated that care was standard apart from the 4 stage intervention).

Rae 2000

MethodsRandomised controlled trial, set in the Diabetes Service, King Edward Memorial Hospital for Women, Perth, Western Australia.


ParticipantsInclusion criteria: gestation < 35 weeks and 6 days, > 110% of ideal body weight for height (adjusted for expected pregnancy weight gain and using a BMI of 25 as equal to 100% ideal body weight), OGTT with fasting plasma glucose > 5.4 mmol/L and/or 2 hour plasma glucose > 7.9 mmol/L.

Exclusion criteria: not stated.


InterventionsIntervention (n = 63): the intervention comprised instruction in a moderately energy restricted diabetic diet providing between 1590-1776 kcal (70% RDA).

Control (n = 54): the control group were instructed in a diabetic diet which was not energy restricted, providing approximately 2010-2220 kcal a day.


OutcomesWeight gain, pre-eclampsias, induction of labour, caesarean delivery, shoulder dystocia, birthweight > 4000 gm, birthweight > 90th centile, assisted delivery.

Weight gain was calculated as the difference between prepregnancy weight and delivery weight.


NotesAge (intervention, control) 30.2, 30.6 years.

Gestation at diagnosis(intervention, control) 28.1 ± 5.8, 28.3 ± 4.6 weeks.

BMI at diagnosis (intervention, control) 37.9 ± 0.7, 38.0 ± 0.7 kg/m².


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNot stated.

Allocation concealment (selection bias)Low riskWomen were allocated at random using opaque numbered envelopes.

Blinding (performance bias and detection bias)
All outcomes
Low riskBoth participants and the Diabetes Service staff were blinded to the allocation to diet group. 

Medical staff were blinded to the group allocation of each participant.

Incomplete outcome data (attrition bias)
All outcomes
Low riskLoss to follow-up 6.4% (8), 4 for each group.         

Selective reporting (reporting bias)Unclear riskCould not be determined.

Other biasLow riskThe groups were similar in level of education, employment, racial distribution, and alcohol and cigarette consumption.

There were no significant differences at enrolment in weight, or energy expenditure.

Rhodes 2010

MethodsRandomised controlled trial (pilot study), set in Beth Israel Deaconess Medical Center, Boston, MA, and Children’s Hospital Boston, Boston, MA, USA.


ParticipantsInclusion criteria: pregnant women with prepregnancy or 1st trimester BMI equal to or greater than 25 kg/m² and less than 45 kg/m², singleton pregnancy, willing to consume the diets for duration of pregnancy, participant to be at week 28 or less of pregnancy at baseline visit.

Exclusion criteria: smoking during pregnancy, major medical illness (e.g., diabetes mellitus, hypertension, thyroid disease), taking prescription medication known to affect body weight, alcohol consumption during pregnancy, intention to deliver infants in the environment outside of Beth Israel Deaconess MedicalCenter, Boston, high level of physical activity.


InterventionsIntervention group 1: nutrition education, dietary counselling, and a low-GL diet.

Intervention group 2: nutrition education, dietary counselling, and a low-fat diet.


OutcomesMaternal outcome: weight change

Infant outcome: macrosomia, large-for-gestational age, caesarean delivery.


Notes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskRandomly “permuted blocks of 2 and 4 preventing anticipation of future assignments.

Allocation concealment (selection bias)Low riskSeparate random assignment envelopes for each stratum. Random assignment envelopes were prepared by the hospital clinical trials unit.

Blinding (performance bias and detection bias)
All outcomes
Low riskThe following staff were blinded to group assignment: obstetricians who provided clinical care to subjects; nurses who measured maternal body weight and blood pressure, collected and processed maternal blood samples, and analysed urinalyses; labour and delivery room nurses who obtained birthweight; laboratory staff who analysed maternal blood; and staff who performed data entry. Staff who performed maternal body composition analysis, 24-h dietary recalls, and infant anthropometric measurements “were predominantly, but not always”, blinded due to logistical considerations. Formal blinding of subjects was not possible, although subjects were not informed of their group assignments.

Incomplete outcome data (attrition bias)
All outcomes
Unclear risk46 women were randomised and infant outcomes were available for 45. There was some loss to follow-up among women with outcome data at 36 weeks available for 38. Reasons for loss were explained and loss was reasonably balanced across groups. It was stated that analysis was by randomisation group irrespective of whether or not women received the intended intervention.

Selective reporting (reporting bias)Unclear riskAssessment from published study report.

Other biasLow riskBaseline characteristics of subjects did not differ between intervention groups.

Santos 2005

MethodsRandomised clinical trial, set in a referral centre prenatal clinic in Porto Alegre, Brazil, during the period 2000–2002.


ParticipantsInclusion criteria: healthy, nonsmoking pregnant women, aged 20 years or more, of gestational age less than 20 weeks, having a BMI between 26 and 31 kg/m² (corresponding to a prepregnancy BMI of 25-30 kg/m²) (overweight), and without diabetes or hypertension.

Exclusion criteria: not stated.


InterventionsIntervention (n = 37): the intervention consisted of a program of supervised physical exercise of 60 minutes duration, performed 3 times per week for 12 weeks. Each session consisted of 5-10 minutes of warm up, 30 minutes of heart rate-monitored aerobic activity, 10-15 minutes of exercise involving upper and lower limbs, and 10 minutes of stretching and relaxation. Aerobic activities were always performed between 50% and 60% of the maximum predicted heart rate, never exceeding 140 beats per minute. The exercises followed the recommendations concerning physical activity practice during pregnancy according to the American College of Sports Medicine, and the American College of Obstetricians and Gynecologists.

Control (n = 35): the control group participated in once-weekly sessions that included relaxation (respiratory exercises and light stretching but no aerobic or weight-resistance exercises) and focus group discussions concerning maternity. Control participants were neither encouraged to exercise nor discouraged from exercising.


OutcomesWeight gain, low birthweight, prematurity.

Weight gain was calculated from different between weight at baseline and weight after 12 weeks of intervention.


NotesAt baseline; age (exercise, control) 26.0 ± 3.4, 28.6 ± 5.9 years.

BMI (exercise, control) 28.0 ± 2.1, 27.5 ± 2.1 kg/m².

Gestational age (exercise, control) 17.5 ± 3.3, 18.4 ± 3.9 weeks.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskWomen were randomised following a blocked sequence generated from a random number table by a statistician not participating in other aspects of the study.

Allocation concealment (selection bias)Low riskThe study coordinator implemented the randomisation by using numbered, opaque envelopes.

Blinding (performance bias and detection bias)
All outcomes
Low riskThe intervention consisted of an unblinded program of supervised physical exercise.

The same cardiologist, blinded to treatment allocation, performed both tests.

The anaerobic threshold was determined by review of the gas exchange curves by 2 cardiologists working independently and blinded to treatment allocation.

Incomplete outcome data (attrition bias)
All outcomes
High riskLoss to follow-up 22%, 19.6%, and 23.9% in intervention and control groups.                                                

Selective reporting (reporting bias)Unclear riskCould not determine.

Other biasHigh riskWomen in the intervention group were somewhat younger, had higher physical activity, and were earlier in their pregnancy.

Silverman 1971

MethodsRandomised controlled trial, set in private practice of 1 of the physicians, Los Angeles, California.


ParticipantsPregnant women who were either overweight or gaining weight at an excessive rate. Patients from upper middle class or high social economic groups. There was no other basis for selection or exclusion of participants.

Average age 24.8 and 25.0 years.


InterventionsIntervention (n = 37): diethylpropion hydrochloride tablet, 75 mg.

Control (n = 38): placebo tablet.


OutcomesWeight change at each stage of gestation.


NotesAge (intervention, control): 24.8, 25.0 years.

Average gestation age started medication (intervention, control): 28, 25 weeks.

BMI (intervention, control): 21.74, 22.45 kg/m².

No standard deviations for continuous outcomes were reported.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskUsed a table of random numbers to assign the patients to active or placebo tablets.

Allocation concealment (selection bias)Unclear riskNo information provided.

Blinding (performance bias and detection bias)
All outcomes
Low riskDouble blind procedure.

Incomplete outcome data (attrition bias)
All outcomes
High riskThere was a vastly difference drop-out rate between the 2 groups, 10/38 in the intervention group and 28/37 in the control group.

Selective reporting (reporting bias)Unclear riskCould not determine.

Other biasLow riskThe pretreatment characteristics were similar.

Thornton 2009

MethodsRandomised controlled trial, set in the ambulatory obstetric clinics of 3 tertiary care medical centres - Morristown Memorial Hospital, St Luke’s-Roosevelt Hospital Center, and Jamaica Hospital Medical Center. Each study site was an urban, public clinic of a teaching hospital, New York Medical College.


ParticipantsInclusion criteria: pregnant with a single fetus between 12 and 28 weeks of gestation that had a BMI greater than or equal to 30 kg/m².

Exclusion criteria: patients with pre-existing diabetes, hypertension, or chronic renal disease.


InterventionsIntervention (n = 116): monitored group; counselled in nutrition by a registered dietitian and given a more detailed dietary intake protocol. The nutrition program for the monitored patients followed dietary guidelines similar to those used in patients with the diagnosis of gestational diabetes. The women in this group were asked to record in a diary all of the foods and beverages eaten during each day.

Control (n = 116): unmonitored group; counselled in nutrition by a registered dietitian regarding conventional prenatal nutrition guidelines.


OutcomesWeight gain, weight retention (calculated from the difference between weight at 6 weeks' postpartum and weight at baseline).

GDM, pre-eclampsia, gestational hypertension, haemorrhage/infection postpartum, preterm delivery (< 37 weeks), labour induction, caesarean delivery, macrosomal infant (> 4500 gm).

Weight gain was weight difference between the baseline(12-28 weeks) pregnancy weight and weight before delivery.


NotesAge (intervention, control) 26.8, 27.3.

BMI (intervention, control) 37.41 ± 7.01, 38.22 ± 7.48 kg/m².


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskA random-number table was used to assign each consecutively numbered envelope to either the study or control group in blocks of 10.

Allocation concealment (selection bias)Low riskEnvelopes were prepared and sequentially numbered. A card indicating the assigned group was placed in the envelope, and the envelope was sealed.

Blinding (performance bias and detection bias)
All outcomes
Unclear riskCould not determine.

Incomplete outcome data (attrition bias)
All outcomes
Low riskThe intention-to-treat principle was performed. Loss to follow-up 9.7%.

Selective reporting (reporting bias)Unclear riskCould not determine.

Other biasLow riskDemographic data for the randomised groups were comparable.

Vitolo 2011

MethodsRandomised controlled trial (pilot study), set in primary care settings in Porto Alegre, Brazil.


ParticipantsInclusion criteria: gestational age between 10 and 29 weeks; women attending the prenatal care unit of the health unit

Exclusion criteria: positive testing for HIV, previous diagnostic of diabetes, hypertension, anaemia or another condition that needed a special diet and age over 35 years.


InterventionsIntervention group: (159 women) weight and diet were assessed at recruitment. The aim of the intervention was to improve diet and encourage weight-appropriate weight gain in pregnancy. For low weight women, the priority was increasing the energetic density of the meals. For normal weight women, daily consumption of vegetables, greens, fruit and water were encouraged and women were advised to restrict consume of fat-rich foods and oil in cooking. For the overweight women, the intervals between meals were prioritised and women were encouraged to restrict their consumption of snacks. Women received a further interview 1 month later to reinforce messages.

Control group: (162 women) women did not receive any special intervention but were informed about their weight and nutritional status and advised to seek professional help if they were under- or over-weight. Their doctors were also provided with the results of the nutritional evaluation.


OutcomesWeight gain.


Notes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)High riskNo sequence generation in advance of randomisation. Women were randomised by means of a dark pouch with 2 equal sized cubes containing the term intervention in 1 and control in the other.

Allocation concealment (selection bias)High risk2 cubes were concealed in a dark pouch and 1 was removed at the point of randomisation which indicated allocation. (It is possible that this could be changed by the person carrying out randomisation.)

Blinding (performance bias and detection bias)
All outcomes
Unclear riskThe impact of lack of blinding on the outcomes measured (weight gain) is not clear.

Incomplete outcome data (attrition bias)
All outcomes
Low risk315 women accepted participation in the study.There were 307 women with anthropometric data collected in the last trimester.

Selective reporting (reporting bias)Unclear riskThe results relate to the number of women with excessive or low weight gain at different gestational ages.

Other biasUnclear riskRisk of bias assessment from translated notes.

Wolff 2008

MethodsRandomised controlled trial, set in Copenhagen, Denmark.


ParticipantsInclusion criteria: pregnant obese women (BMI > 30 kg/m²), nondiabetic non-smoking and Caucasian recruited at 15 ± 3 weeks of gestation. 

Exclusion criteria: smoking, age < 18 or > 45, multiple pregnancy, or medical complication.


InterventionsIntervention (n = 23): restriction of gestational weight gain to 6-7 kg by 10 consultation of 1-hour each with trained dietitian. The women were instructed to eat a healthy diet according to the official Danish dietary recommendations (% fat, protein, CHO, 30, 15-20, 50-55%). The energy intake was restricted based on individually estimated energy requirements and estimated energetic cost of fetal growth.

Control (n = 27): the control group had no consultations with the dietitian and had no restrictions on energy intake or gestational weight gain.

All participants followed the routine clinical schedule.


OutcomesWeight gain, weight retention at 4 weeks postpartum, pre-eclampsias, caesarean delivery.

Weight gain was calculated as difference between self-reported prepregnancy weight and weight just before delivery.


NotesAge (intervention, control) 28 ± 4, 30 ± 5 years.

Gestational age (intervention, control) 15 ± 2, 16 ± 3 weeks.

BMI at inclusion visit (intervention, control) 34.9 ± 4, 34.6 ± 3 kg/m².


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskThe computerised randomisation took place after the women had given written informed consent.

Allocation concealment (selection bias)Unclear riskNo information provided.

Blinding (performance bias and detection bias)
All outcomes
Low riskThe physicians and midwives were blinded in regard to the treatment assignment, and women were asked not to reveal their allocation.

Incomplete outcome data (attrition bias)
All outcomes
High riskLoss to follow-up 24%: 17.8% in intervention group, 28.9% in control group.

Selective reporting (reporting bias)Unclear riskCould not determine.

Other biasLow riskBaseline characteristics were similar.

 
Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion

Breslow 1963Non-randomised controlled trial.

Campbell 2004Participants included pregnant and nonpregnant women.

Faucher 2008It was not clear that women in this study were pregnant (community weight loss intervention).

Gray-Donald 2000Non-randomised controlled trial.

Hausenblas 2008Participants included both pregnant and postpartum women.

Ismail 1990Not a relevant intervention.This study examined the use of cefoxitin (an antibiotic) for the prevention of post-cesarean-section infection.

Kinnunen 2007Non-randomised controlled trial.

Moses 2007Participants were postpartum women (a follow-up study of Moses 2006).

Olson 2004Non-randomised controlled trial.

Te Morenga 2011This study did not include pregnant women.

Walker 1966Non-randomised controlled trial.

Wisner 2006Participants were postpartum women.

 
Characteristics of studies awaiting assessment [ordered by study ID]
Leiferman 2011

MethodsRandomised controlled trial.

ParticipantsPregnant women of the My Baby My Move (MBMM) program.

InterventionsAn antenatal community-based physical activity intervention.

OutcomesMinutes per week of moderate-intensity physical activity.

Notes

Mohebi 2009

MethodsQuasi-experimental randomised and controlled study.

Participants110 pregnant women referring to Gonabad’s health centres.

InterventionsNutrition education program on the recommended weight gain during pregnancy; Application of Health Belief Model.

OutcomesWeight gain during pregnancy.

Notes

 
Characteristics of ongoing studies [ordered by study ID]
Althuizen 2006

Trial name or titleDesign of the New Life(style) study: a randomised controlled trial to optimise maternal weight gain during pregnancy.

MethodsRandomised controlled trial.

ParticipantsLocation: The Netherlands.

The aim is to include 275 participants in the study.

Women are eligible for participation when they are:

1) expecting their 1st child;

2) able to read, write, and speak Dutch;

3) within their 1st 14 weeks of pregnancy.

InterventionsIntervention: the New Life(style) intervention program consists of 5 individual counselling modules together with a general information brochure.

Control: usual care.

OutcomesPrimary outcomes: body weight, BMI, and skinfold thickness.

Secondary outcomes: physical activity, nutrition and blood levels of factors that are associated with energy homeostasis.

Starting dateFebruary 2005.

Contact informationEllen Althuizen; e.althuizen@vumc.nl

Department of Public and Occupational Health, EMGO-Institute, VU UniversityMedical Center, Amsterdam, The Netherlands.

NotesOnly protocol has been published. Ongoing for the full publication.

Brand-Miller 2010

Trial name or titleA pregnancy intervention to reduce postprandial glucose excursions in the primary prevention of paediatric obesity.

MethodsRandomised controlled trial.

ParticipantsLocation: Australia.

Target number of participants: 1650.

Inclusion: healthy pregnant women at 12 to 16 weeks' gestation who agree to be randomised.

Exclusion:

1. women with pregestational diabetes;
2. multiple birth;
3. assisted reproduction;
4. special diet or referred to a dietitian for other reasons.

InterventionsA conventional healthy diet or a low glycaemic index diet from 12 to 16 weeks' gestation for the remainder of pregnancy.

OutcomesPrimary outcomes:

1. prevalence of large gestational age at birth (more than 90th centile);
2. prevalence of childhood obesity as determined by BMI.

Secondary outcomes:

1. prevalence of gestational diabetes;
2. ponderal index;
3. prevalence of small-for-gestational age.

Starting date01/01/2008.

Contact informationProf Jennie Brand-Miller; j.brandmiller@mmb.usyd.edu.au

Human Nutrition Unit, University of Sydney, NSW 2006 Australia.

Notes

Brand-Miller 2011

Trial name or titleA randomised, 2-arm parallel dietary intervention study to compare the effects of consuming a low glycaemic diet or wholegrain high fibre diet on infant birthweight and body composition, complications related to GDM and progression to GDM diagnosis in women at high-risk of GDM.

MethodsRandomised controlled trial.

ParticipantsPregnant: between 14-20 weeks of gestation and 1 or more of the following GDM risk factors: 1. Age: > 30 years 2. Family history of type 2 diabetes- 1st-degree relatives with type 2 diabetes 3. Overweight or obese: Prepregnancy BMI > 30 (Kg/m²) 4. Past history of GDM or glucose intolerance 5. History of ‘large-for-gestational-age’ babies: Previous baby > 4 kg 6. Belonging to a high-risk ethnic group: Aboriginal or Torres Strait Islander, Polynesian, Middle Eastern, Indian and Asian. 7. Ability to read and understand participant information and consent form 8. Ability to comply with the scheduled visits and dietary advice.

Target sample size: 150.

InterventionsIntervention group: low GI diet, consisting of protein (15%–25%), fat (30%–35%) and carbohydrate (45%–50%) content and a low dietary GI less than 50. Carbohydrate choices for the low GI diet will include pasta, low GI rice, low GI breakfast cereals and breads. The intervention duration is from 20 weeks' gestation until birth. The intervention involves 5 consultations with an accredited practising dietitian (APD) at 20, 24, 28, 32 and 36 weeks of gestation. At weeks 20 and 36, the approximate duration of each dietary education session is 60 minutes. At weeks 24, 28 and 32, the approximate duration of each dietary education session is 30 minutes. Handouts and recipes will be provided, and the participants will have access to the research dietitian via phone throughout their participation period. Participants will receive a food basket at each of the 5 education sessions with the dietitian (at week 20, 24, 28, 32 and 36 weeks of gestation) containing foods that are low GI to improve their compliance and understanding of the advised food choices.

Control group: wholegrain high fibre diet, consisting of protein (15%–25%), fat (30%–35%) and carbohydrate (45%–50%) content and a GI of approximately 60 (average GI of a normal healthy diet). Carbohydrate choices for the wholegrain high fibre diet will include potatoes, brown rice, wholemeal breads and wholegrain breakfast cereals. The intervention duration is from 20 weeks' gestation until birth. The intervention involves 5 consultations with an accredited practising dietitian (APD) at 20, 24, 28, 32 and 36 weeks of gestation. At weeks 20 and 36, the approximate duration of each dietary education session is 60 minutes. At weeks 24, 28 and 32, the approximate duration of each dietary education session is 30 minutes. Handouts and recipes will be provided, and the participants will have access to the research dietitian via phone throughout their participation period. Participants will receive a food basket at each of the 5 education sessions with the dietitian (at week 20, 24, 28, 32 and 36 weeks of gestation) containing foods that are wholegrain high fibre to improve their compliance and understanding of the advised food choices.

OutcomesPrimary outcome: birthweight Z-score,

Secondary outcomes: detection of GDM, need for insulin use, ponderal index, infant body composition, fasting blood glucose level, maternal weight gain, pregnancy complications, dietary assessment, the FTO gene, inflammatory markers such as Interleukin 6 (IL-6), leptin and C-Reactive Protein (CRP)

Starting date30/09/2010

Contact informationProfessor Jennie Brand-Miller, j.brandmiller@usyd.edu.au

Human Nutrition Unit, School of Molecular Bioscience, G08- Biochemistry Building, The University of Sydney NSW 2006

Notes

Brownfoot 2011

Trial name or titleWeighing in Pregnancy.

MethodsRandomised controlled trial.

ParticipantsPregnant women attending for antenatal care at < 20 weeks' gestation 18-45 years. Excluded multiple gestation or medical or psychiatric illness. (Target sample size 650.)

InterventionsWeighing as part of each antenatal visit compared with routine care.

OutcomesWeight gain within IOM and WHO recommendations; medical complications of pregnancy (pre-eclampsia, hypertension, gestational diabetes); need for induction of labour; mode of delivery; postpartum complication; infant birthweight; macrosomia and complications relating to macrosomia.

Starting date1st January 2010.

Contact informationfiona.brownfoot@thewomens.org.au

Notes

Chasan-Taber 2009

Trial name or titleA randomised controlled trial of prenatal physical activity to prevent gestational diabetes: design and methods.

MethodsRandomised controlled trial.

A blocked randomisation is used such that both treatment groups are assigned an equal number of times in each set of 4 sequentially enrolled subjects.

ParticipantsLocation: Bay State Medical Center in western Massachusetts.

Target number of participants: 364.

Inclusion criteria: women are sedentary, with a diagnosis of GDM in a prior pregnancy defined according to American Diabetes Association (ADA) criteria

Exclusion criteria: age < 18 or > 40 years, history of diagnosis of diabetes outside of pregnancy, hypertension, heart disease or chronic renal disease, current medications that adversely influence glucose tolerance, > 16 weeks' gestation, contraindications to participating in moderate physical activity, inability to read English at a 6th grade level, self-reported participation in > 30 minutes of moderate-intensity or vigorous-intensity exercise on > 3 days/week, and non singleton pregnancy.

InterventionsExercise intervention: person education on exercise followed by weekly, biweekly and monthly mail and telephone follow-up.

Health and wellness intervention: person education health and wellness followed by weekly and monthly mail and telephone follow-up.

OutcomesMaternal weight gain (change in weight from pregravid to delivery), birthweight, Apgar score, caesarean delivery, macrosomia (> 4000 gm) and large-for-gestational age, defined as newborn weight the 90th percentile for completed gestational weeks using cutoff points defined by Oken.

Starting dateApril 2010.

Contact informationLisa Chasan-Taber; lct@schoolph.umass.edu

Megan Ward Harvey, meward@schoolph.umass.edu

Notes

Dodd 2010a

Trial name or titleLimiting weight gain in overweight and obese women during pregnancy to improve health outcomes: a randomised trial.

MethodsRandomised controlled trial.

ParticipantsLocation: Australia.

Target sample size: 2574.

Inclusion criteria: pregnant women with a singleton, live gestation between 10-20 weeks who are obese or overweight (defined as a BMI greater that 25kg/m²).

Exclusion criteria: women with multiple pregnancy, or type 1 or type 2 diabetes diagnosed prior to pregnancy. There is no age range criteria for this trial.

InterventionsWomen will be randomised to the dietary and lifestyle advice group or the standard care group.

Dietary and lifestyle advice group will receive a comprehensive intervention to limit weight gain in pregnancy that includes a combination of dietary, exercise and behavioural strategies.

Standard care group will continue to receive their pregnancy care according to local hospital guidelines, which does not currently include routine provision of dietary, lifestyle and behavioural advice).

OutcomesPrimary outcome: infant large-for-gestational age at birth (defined as birthweight > 90th centile for gestational age).

Secondary outcomes: adverse outcomes for the infant including preterm birth, adverse outcomes for the women, maternal quality of life and emotional well being and costs of health care.

Starting date1/02/2008.

Contact informationDr Jodie Dodd; jodie.dodd@adelaide.du.au

University of Adelaide, Obstetrics & Gynaecology Women's and Children's Hospital Level 1, Queen Victoria Building 72 King William Road North Adelaide SA 5006

Notes

Downs 2011

Trial name or titleActive Moms (A randomised physical activity intervention for pregnant women).

MethodsRandomised controlled trial.

ParticipantsPregnant women (inclusion and exclusion criteria not described).

Interventions2 physical activity interventions and a control group. 1 group received a structured intervention with face to face physical activity education, motivational support and moderate physical activity on 2 days per week for 70mins with an instructor. The 2nd group (lifestyle support) received educational support via mailed materials and phone support. The control group received standard care.

OutcomesPerformance (physical activity).

Starting dateNot clear.

Contact informationdsd11@psu.edu

NotesStudy reported in brief abstract with preliminary findings.

Ferrara 2010

Trial name or titleDiet, exercise and breastfeeding intervention program for women with gestational diabetes (DEBI Trial).

MethodsRandomised, single blind (outcomes assessor), active control, parallel assignment, efficacy study.

ParticipantsLocation: USA.

Inclusion criteria: diagnosis of GDM.

Exclusion criteria: ever diagnosed with diabetes when not pregnant, ever diagnosed with cardiovascular disease, ever diagnosed with lung disease, haemoglobin < 9.5 mg/dL, haematocrit less than 30%, SBP >= 140 or DBP >= 90 in the last month.

Diagnosis of thyroid disease in the last month.

InterventionsIntervention: experimental women receiving the behavioural: diet, exercise, and breastfeeding intervention.

Control: standard care.

OutcomesPrimary outcome: postpartum weight retention.

Secondary outcomes: postpartum levels of plasma insulin, markers of insulin resistance, adiponectin, dietary fat, physical activity, and breastfeeding duration.

Starting dateSeptember 2005.

Contact informationAssiamira Ferrara,

Kaiser Permanente Division of Research, California, United States, 94612

NotesThis study has been completed.

No publications provided yet. Ongoing for the publication.

Haakstad 2010

Trial name or titleEffect of regular exercise in prevention of excessive weight gain in pregnancy.

MethodsRandomised, single blind (investigator).

ParticipantsLocation: Norway.

Target sample size: 105.

Inclusion criteria: primiparous women who have not participated in a structured exercise program, including significant amounts of walking for the past 6 months, ability to read, write and speak Norwegian, and to be within their 1st 24 weeks of pregnancy.

Exclusion criteria: severe heart disease, pregnancy-induced hypertension, history of more than 2 miscarriages, persistent bleeding after week 12 of gestation, poorly controlled thyroid disease, poorly controlled pre-eclampsia, and/or other diseases that could interfere with participation, live too far from the university to be able to attend weekly training groups.

InterventionsIntervention: supervised exercise for the prevention of high weight gain.

Each session starts with 5 minutes warm up, followed by 30 minutes of aerobic activity, including cool down. This is followed by 15 minutes of strength training of the upper and lower limbs, and special focus on the deep abdominal stabilisation muscles. The last 5 minutes contains stretching, relaxation and body awareness exercises. The exercise-program follows the ACOG exercise prescription, and all aerobic activities will be performed at moderate intensity (60%-70% of maximal heart rate), measured by ratings of perceived exertion at 11-14 (somewhat hard) on the 6-20 Borg's rating scale. Control: participants are neither encouraged nor discouraged from exercising.

OutcomesPrimary outcomes: overall weight gain during pregnancy and proportion of participants exceeding weight gain above IOM recommendations. (Time frame: week 36-38 of pregnancy.)

Secondary outcomes: pregnancy complications, relationship between oxygen consumption, heart rate and blood lactate concentration at submaximal work loads, infant birthweight, length of labour and complications during delivery. (Time frame: week 36-38 of gestation.)

Starting dateNovember 2007.

Contact informationLene Haakstad; lene.haakstad@nih.no

Norwegian School of Sport Sciences

NotesSome results was published in the abstract (Haakstad 2009). Ongoing for the full publication.

Ko 2010

Trial name or titleEffect of physical activity on metabolic syndrome in pregnancy and fetal outcome.

MethodsRandomised controlled trial, single blind (investigator).

ParticipantsLocation: United States, Washington.

Target number of participants: 100.

Inclusion criteria: pregnant women 18-45 years old receiving prenatal care at MAMC.

Exclusion criteria: women do not have a gallbladder, do not speak English, over 14 weeks pregnant at study entry, do not plan to deliver at MAMC, have medical contraindications, unwilling to participate in exercise intervention program, < 18 years of age, currently engaged in a regular vigorous exercise program.

InterventionsIntervention group will exercise 3 times per week at moderate-vigorous intensity for 45 minutes per session through their 36 week of pregnancy.

Control group women will continue their usual physical activity throughout pregnancy.

OutcomesPrimary outcome: central adiposity.

Secondary outcomes: leptin levels, glucose insulin, cholesterol, fetal adiposity, neonatal adiposity.

Starting dateOctober 2007.

Contact informationCynthia W Ko, University of Washington.

Notes

McAuliffe 2010

Trial name or titleA randomised control trial of low glycaemic index carbohydrate diet versus no dietary intervention in the prevention of recurrence of macrosomia.

MethodsRandomised controlled trial.

Randomisation will be achieved using computer-generated allocations in a ratio of 1:1 contained in sealed opaque envelopes.

ParticipantsLocation: the National Maternity Hospital, Dublin, Ireland.

Target number of participants: 700.

Inclusion: secundigravid women of reproductive age (greater than 18 years and less than 45 years) whose 1st baby was macrosomic (birthweight > 4000 gm) will be recruited at 1st booking visit from the antenatal clinic at the National Maternity Hospital.

Exclusion: diabetes, other medical disorders and those with poor previous pregnancy outcome.

InterventionsA diet arm: will be commenced on a low glycaemic index diet from 14 weeks' gestation to delivery under dietetic supervision.

A control arm: will receive no dietary intervention.

OutcomesPrimary outcomes: mean birthweight centiles and ponderal indices in each group. Outcomes will be measured at 14 weeks, 28 weeks, 34 weeks, at birth and 3 months postpartum.

Secondary outcomes: maternal weight gain in pregnancy; urinary metabolimics; cord insulin, leptin and IGF-1; placental weight, villous and vascular development.
Outcomes will be measured at 14 weeks, 28 weeks, 34 weeks, at birth and 3 months postpartum.

Starting dateAnticipated start date, 01/01/2007.

Contact informationProfessor Fionnuala McAuliffe; fmcauliffe@nmh.ie

UCD Obstetrics & Gynaecology, UCD School of Medicine and Medical Science, University College Dublin, National Maternity Hospital, Holles Street.

NotesPublication protocol in "Walsh J, Mahony R, Foley M, McAuliffe F. A randomised control trial of low glycaemic index carbohydrate diet versus no dietary intervention in the prevention of recurrence of macrosomia. BMC Pregnancy and Childbirth 2010;10:16.".

A pilot study of feasibility of the trial was published in the abstract of poster presentation of Mahony 2008.

Melo 2010

Trial name or titleEffects of physical exercise during pregnancy on the maternal and perinatal outcomes: a randomised clinical trial.

MethodsRandomised controlled trial.

ParticipantsInclusion criteria: gestational age < 13 weeks, single pregnancy, alive fetus, no previous practice of physical activity.

Exclusion criteria: smoking, chronic maternal diseases, placenta praevia, history of preterm labour, bleeding.

InterventionsIntervention: 2 groups of exercise:

group 1: starting to practice physical exercise at 13 weeks; walking 3 times a week during 1 hour (moderate activity);

group 2: starting to practice physical exercise at 20 weeks; walking 3 times a week during 1 hour (moderate activity).

Control: without exercise practice.

OutcomesPrimary outcome measures: maternal outcomes: preterm labour, weight gain, pre-eclampsias, gestational diabetes. Perinatal outcome: birthweight, Apgar scores, body composition, admission at neonatal intensive care unit.

Secondary outcomes: Doppler flow velocimetry indexes: pulsatility, resistance and A/B relation (uterine arteries, fetal middle cerebral artery and umbilical arteries).

Starting dateApril, 2008.

Contact informationAdriana Melo; asomelo@gmail.com

Melania Amorim, PhD, melamorim@uol.com.br

Universidade Estadual da Paraiba, Campina Grande, Paraiba, Brazil, 58100-000

Notes

Morkved 2010

Trial name or titleEffects of regular exercise during pregnancy.

MethodsRandomised, single blind (outcomes assessor).

ParticipantsLocation: Norway.

Target sample size: 380.

Inclusion criteria: pregnant women who attend the routine ultrasound control at the 3 hospitals at 18 weeks of pregnancy are invited to participate in the study. Women are eligible for the trial if they are healthy, 18 years or more, with a singleton live fetus at the routine ultrasound scan and a normal pregnancy.

Exclusion criteria: pregnancy complications, high risk for preterm labour, pain during pelvic floor muscle contractions, ongoing urinary tract infection, or diseases that could interfere with participation (following recommendations ACOG 2003) . In addition, women who live too far from the hospitals to be able to attend weekly exercise groups will be excluded.

InterventionsIntervention: regular exercise 45-60 minutes minimum 3 times per week.

Control: standard care.

OutcomesPrimary outcomes: gestational diabetes/insulin resistance.

Secondary outcomes: fecal and urinary incontinence (incontinence scores)/lumbopelvic pain: pain intensity 100 mm visual analogue scale, disability rating index/labour.

Starting dateMay 2007.

Contact informationSiv Morkved; siv.morkved@ntnu.no

Department of Community Medicine and General Practice, Norwegian University of Science and Technology and Clinical Service, St Olavs Hospital, Trondheim University Hospital,

Trondheim, Norway, 7489

NotesNot recruiting participants.

Nagle 2011

Trial name or titleContinuity of midwifery care and gestational weight gain in obese women.

MethodsRandomised controlled trial.

Participants214 primiparous women attending 1 of the study hospitals for maternity care with a booking BMI >30 and less than 17 weeks' gestation. Exclusion criteria include inability to speak English, multiple pregnancy, vaginal bleeding or serious medical condition.

InterventionsContinuity of midwifery care compared with routine management.

OutcomesWeight gain; women's experience of care and satisfaction with care; psychological well being.

Starting dateNot clear.

Contact informationcate.nagle@deakin.edu.au

Notes

Oostdam 2009

Trial name or titleDesign of fit for 2 study: the effects of an exercise program on insulin sensitivity and plasma glucose levels in pregnant women at high risk for gestational diabetes.

MethodsRandomised controlled trial.

ParticipantsLocation: The Netherlands.

Target number of participants: 160.

Inclusion criteria: between 14 and 20 weeks of pregnancy, over 18 years of age, sufficiently fluent in Dutch, being able to be moderately physically active, and willingness to give written informed consent.

Exclusion criteria: diagnosed with (gestational) diabetes mellitus before randomisation, hypertension (systolic pressure > 160 mmHg and/or diastolic pressure > 100 mmHg), alcohol abuse (i.e. 2 glasses alcohol or more per day), drug abuse (except for incidental analgesic agents), use of the medication that affects insulin secretion or insulin sensitivity (antiviral, corticosteroids, antihypertensive drugs, all concomitant medication will be discussed), serious pulmonary (COPD, exercise-induced asthma), cardiac, hepatic or renal (serum creatinine < 150 mol/) impairment, malignant disease; serious mental or physical impairment i.e. preventing to understand or implement the study protocol/aim.

InterventionsIntervention group:  receives an exercise program twice a week in addition to usual care. The exercise program consist of aerobic and strength exercises and takes place under close supervision of a physiotherapist.

Control group:  receives usual care given by obstetricians and midwives. Dutch midwives and obstetricians follow closely the health status of each pregnant woman and their unborn child. The 1st appointment is usually between 9th and 12th week of gestation.

OutcomesPrimary maternal outcome measures are fasting plasma glucose and relative increase in insulin resistance. Primary neonatal outcome is birthweight.

Secondary outcome measures are maternal serum triglycerides, HDL, cholesterol and HbA1c, maternal weight gain during pregnancy, maternal physical activity level, foetal growth. Changes in direct healthcare and non-healthcare costs and indirect non-healthcare costs are studies as well.

Starting date14 November 2008.

Contact informationNicolette Oostdam; n.oostdam@vumc.nl

Notes

Parat 2010

Trial name or titleImpact of education during pregnancy in overweight pregnant women (ETOIG).

MethodsRandomised controlled trial.
Masking: single blind (subject).

ParticipantsLocation: Hospital Necker Paris, France.

Target number of participants: 800.

Inclusion criteria: pregnant women who agree the study, BMI > 25 kg/m² (BMI is based on retrospective self reported weight of the patient before pregnancy), no more than 21 weeks of gestation.

Exclusion criteria: younger than 18 years, multiple gestation, high-risk pregnancy, psychiatric pathology, diabetes diagnosed before the inclusion, fetal malformation, history of obesity surgery, no understanding of French language, planning to move to another area.

InterventionsIntervention: therapeutic education; intensive training individual and collective teaching.

Control: placebo comparator; classical follow-up with 2 individual consultations.

OutcomesPrimary outcomes:

-30% reduction of rapid infancy weight gain at 2 years defined as > + 0.67 change in weight SD score. The 0.67 SD represents the difference between the displayed centile lines on standard infant growth charts.

Secondary outcomes:

-reduction of rapid infancy weight gain between 0 and 6 months;

-reduction of the number of children with BMI over 19 at 2 years;

-reduction of incidence of gestational diabetes, pre-eclampsias, HTA during pregnancy, caesarean, fetal macrosomia;

-reduction of spontaneous feeding at 4 months;

-increase of breastfeeding (number of women and duration);

-reduction 1 and 2 years after pregnancy of mother weight and BMI (except 2nd pregnancy);

-reduction of abnormality of lipid and glycaemia test in women, 2 years after the pregnancy.

Starting dateSeptember 2008.

Contact informationSophie Parat; sophie.parat@nck.aphp.fr

Raphael Serreau; raphael.serreau@cch.aphp.fr

Notes

Poston 2010

Trial name or titleImproving pregnancy outcome in obese woman: a feasibility study.

MethodsFeasibility trial.

ParticipantsLocation: United Kingdom.

Target number of participants: 100.

Inclusion: willing and able to give informed consent, pregnant women with booking BMI greater than or equal to 30 kg/m², singleton pregnancy.

Exclusion: pre-existing diabetes mellitus.

InterventionsThe intervention consists of an individualised activity and diet plan. Women will be recruited between 10-16 weeks' gestation and the interventions will continue until delivery. Therefore maximum duration for any 1 woman would be 32 weeks (allowing for her to deliver at 2 weeks post-estimated date of delivery).

The control arm will have blood taken at recruitment and again in late pregnancy. Other than this they will receive usual pregnancy care and advice in accordance with local and national antenatal care guidelines.

OutcomesPrimary outcomes: improved maternal glucose sensitivity, assessed at recruitment (10-16 weeks), and again in the 3rd trimester (32-36 weeks).

Secondary outcomes: reduction in fetal, maternal and pregnancy complications, assessed at recruitment (10-16 weeks), and again in the 3rd trimester (32-36 weeks).

Starting date01/11/ 2008.

Contact informationProfessor Lucilla Poston; Lucilla.poston@kcl.ac.uk

Maternal and Foetal Research Unit 10th Floor North Wing St Thomas Hospital, London

Tel: +44 (0) 20 7188 3639

Notes

Shen 2010

Trial name or titleImpact of diet and exercise activity on pregnancy outcomes (IDEA).

MethodsRandomised, open label.

ParticipantsLocation: Canada.

Inclusion criteria: age 18 years and older, pregnancy < 20 weeks, expressed interest in study and willingness to consent to participate in the study.

Exclusion criteria: obstetric or medical contraindications for exercise according to 2002 SOCG guideline (ruptured membranes, preterm labour, incompetent cervix, hypertensive disorders of pregnancy, growth restricted fetus, placenta previa, persistent bleeding in 2nd or 3rd trimester, significant metabolic, cardiovascular, respiratory or systemic disorder), pre-existing diabetes (except a history of GDM, but not in current pregnancy), multiple gestations.

InterventionsA community-based exercise and dietary intervention.

OutcomesPrimary outcomes: excessive weight gain during pregnancy.

Secondary outcomes: macrosomia, requirement of delivery procedures.

Starting dateJuly 2006.

Contact informationGarry Shen; gshen@ms.umanitoba.ca

University of Manitoba

Notes

Smith 2010

Trial name or titleThe design of a community lifestyle programme to improve the physical and psychological well-being of pregnant women with a BMI of 30 kg/m² or more.

MethodsRandomised controlled trial.

ParticipantsLocation: England.

Enrollment: 400 (200 from each area).

Inclusion criteria: women attending for antenatal care in a 2 UK hospitals with a BMI 30 kg/m² or greater.

Exclusion criteria: aged under 18, intend to move in the next 3 months, take weight control medication or if they have any cautions for starting exercise (this will be determined using the Revised Physical Activity Readiness Questionnaire (PARQ) and the Royal College of Obstetricians and Gynaecologists (RCOG) recommendations).

InterventionsThe lifestyle programme will run for 1.5 hours per week for 10 weeks and is supplementary to standard antenatal care. Women will be invited to the 10-week programme at any stage before 30 weeks' gestation to ensure completion of the programme before their delivery.

The control group will receive routine care.

OutcomesPrimary outcomes: pregnancy weight gain, birthweight, mode of birth, and method of infant feeding at hospital discharge: psychological outcomes include self-efficacy, well-being, and goal attainment

Secondary outcomes: women's experience of pregnancy and healthcare services, amount of physical activity, food intake, and the suitability of the intervention components.

Starting dateOctober 2011 (recruitment).

Contact informationProfessor Tina Lavender; tina.lavender@manchester.ac.uk

University of Manchester, Oxford Road, Manchester. M13 9PL

United Kingdom

Notes

Vinter 2010

Trial name or titleLifestyle and pregnancy: the clinical effect of lifestyle intervention during pregnancy in obese women.

MethodsRandomised, open label, parallel assignment.

ParticipantsLocation: Denmark.

Enrollment: 360.

Inclusion criteria: singleton pregnant, BMI ≥ 30 and ≤ 45 kg/m².

Exclusion criteria: chronic diseases, not Danish speaking, abuse of alcohol or drugs, preterm delivery in earlier pregnancies.

InterventionsLifestyle intervention: the intervention is composed of individual dietician counselling and physical training. The physical training includes weekly aerobic exercises in a fitness centre and lifestyle coaching in small groups.

OutcomesPrimary outcomes: caesarean section, GDM, hypertension/pre-eclampsias, large-for-gestational age and admission to neonatal intensive care unit. (Time frame: until 6 months postpartum.)

Secondary outcomes: metabolic markers. (Time frame: until 6 months postpartum.)

Starting dateOctober 2007.

Contact informationChristina A. Vinter; c.vinter@dadlnet.dk

Odense University Hospital

NotesThis study is not yet open for participant recruitment.

Weeks 2011

Trial name or titleEfficacy of Metformin in Pregnant Obese women - a randomised trial (EMPOWaR)

MethodsRandomised controlled trial.

ParticipantsWomen with BMI of 30 or more between 12-16 weeks' gestation.

InterventionsMetformin vs placebo.

OutcomesInfant birthweight, maternal insulin resistance, and other maternal and infant outcomes.

Starting dateNot clear.

Contact informationaweeks@liverpool.ac.uk

NotesPersonal communication (trial information sheet).

 
Comparison 1. Interventions to prevent excessive weight gain versus standard care or routine care (general population)

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Excessive weight gain4Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    1.1 Behavioural counselling versus standard care
2247Risk Ratio (M-H, Fixed, 95% CI)0.72 [0.54, 0.95]

    1.2 Regular weight measurement versus standard care
1152Risk Ratio (M-H, Fixed, 95% CI)0.57 [0.23, 1.40]

    1.3 Exercise intervention plus dietary intervention versus standard care
145Risk Ratio (M-H, Fixed, 95% CI)0.63 [0.23, 1.68]

 2 Weight gain (kg)8Mean Difference (IV, Fixed, 95% CI)Subtotals only

    2.1 Behavioural counselling versus standard care
3341Mean Difference (IV, Fixed, 95% CI)-1.39 [-2.48, -0.30]

    2.2 Regular weight measurement versus standard care
1152Mean Difference (IV, Fixed, 95% CI)-0.75 [-1.98, 0.48]

    2.3 Regular supervised exercise versus routine care
167Mean Difference (IV, Fixed, 95% CI)-2.0 [-3.26, -0.74]

    2.4 Dietary counselling versus standard care (placebo)
1171Mean Difference (IV, Fixed, 95% CI)0.0 [-1.53, 1.53]

    2.5 Exercise intervention plus dietary intervention versus standard care
2170Mean Difference (IV, Fixed, 95% CI)-2.03 [-2.99, -1.07]

    2.6 Dietary counselling plus probiotics versus standard care (placebo)
1170Mean Difference (IV, Fixed, 95% CI)0.20 [-1.22, 1.62]

 3 Low weight gain2Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    3.1 Behavioural counselling versus standard care
2247Risk Ratio (M-H, Fixed, 95% CI)1.33 [0.74, 2.37]

 4 Preterm birth3Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    4.1 Regular weight measurement versus standard care
1235Risk Ratio (M-H, Fixed, 95% CI)0.67 [0.15, 2.93]

    4.2 Behavioural counselling versus standard care
2243Risk Ratio (M-H, Fixed, 95% CI)0.75 [0.36, 1.58]

 5 Pre-eclampsia3Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    5.1 Behavioural counselling versus standard care
2243Risk Ratio (M-H, Fixed, 95% CI)0.34 [0.10, 1.22]

    5.2 Regular weight measurement versus standard care
1235Risk Ratio (M-H, Fixed, 95% CI)2.69 [0.55, 13.03]

 6 Caesarean delivery5Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    6.1 Behavioural counselling versus standard care
3343Risk Ratio (M-H, Fixed, 95% CI)0.78 [0.53, 1.16]

    6.2 Regular weight measurement versus standard care
1235Risk Ratio (M-H, Fixed, 95% CI)1.22 [0.82, 1.82]

    6.3 Regular supervised exercise versus routine care
167Risk Ratio (M-H, Fixed, 95% CI)0.68 [0.29, 1.57]

 7 Energy intake (kj)1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    7.1 Dietary counselling versus standard care (placebo)
1135Mean Difference (IV, Fixed, 95% CI)-170.00 [-694.76, 350.76]

    7.2 Dietary counselling plus probiotics versus standard care (placebo)
1132Mean Difference (IV, Fixed, 95% CI)104.0 [-421.32, 629.32]

 8 Fibre intake (gm)1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    8.1 Dietary counselling versus standard care (placebo)
1135Mean Difference (IV, Fixed, 95% CI)1.10 [-0.91, 3.11]

    8.2 Dietary counselling plus probiotics versus standard care (placebo)
1132Mean Difference (IV, Fixed, 95% CI)1.70 [-0.32, 3.72]

 9 Physical activity score2Mean Difference (IV, Fixed, 95% CI)Subtotals only

    9.1 Exercise intervention plus dietary intervention versus standard care
2170Mean Difference (IV, Fixed, 95% CI)0.63 [0.35, 0.91]

 10 Physical activity (reporting 30 min exercise on most days)1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    10.1 Interactive diet and exercise video counselling versus routine care
1287Risk Ratio (M-H, Fixed, 95% CI)1.31 [0.92, 1.86]

 11 Infant birthweight > 4000 gm4Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    11.1 Behavioural counselling versus standard care
2243Risk Ratio (M-H, Fixed, 95% CI)2.19 [0.63, 7.60]

    11.2 Regular supervised exercise versus routine care
167Risk Ratio (M-H, Fixed, 95% CI)0.65 [0.12, 3.63]

    11.3 Exercise intervention plus dietary intervention versus standard care
145Risk Ratio (M-H, Fixed, 95% CI)0.44 [0.09, 2.15]

 12 Infant birthweight > 90th centile1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    12.1 Regular weight measurement versus standard care
1235Risk Ratio (M-H, Fixed, 95% CI)0.65 [0.27, 1.56]

 13 Infant birthweight < 2500 gm2Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    13.1 Behavioral counselling versus standard care
2243Risk Ratio (M-H, Fixed, 95% CI)1.03 [0.40, 2.63]

 14 Infant birthweight < 10th centile1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    14.1 Regular weight measurement versus standard care
1235Risk Ratio (M-H, Fixed, 95% CI)0.67 [0.29, 1.53]

 15 Neonatal hypoglycaemia1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    15.1 Regular weight measurement versus standard care
1235Risk Ratio (M-H, Fixed, 95% CI)2.69 [0.28, 25.44]

 16 Shoulder dystocia1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    16.1 Regular weight measurement versus standard care
1235Risk Ratio (M-H, Fixed, 95% CI)0.90 [0.06, 14.14]

 17 Maternal weight retention (kg)1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    17.1 Behavioural counselling versus standard care
139Mean Difference (IV, Fixed, 95% CI)-1.80 [-4.95, 1.35]

 18 Maternal weight gain above prepregnancy weight at 6 months postpartum2Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    18.1 Behavioural counselling versus standard care
1186Risk Ratio (M-H, Fixed, 95% CI)0.80 [0.67, 0.97]

    18.2 Exercise intervention plus dietary intervention versus standard care
1125Risk Ratio (M-H, Fixed, 95% CI)0.35 [0.19, 0.63]

 
Comparison 2. Interventions to prevent excessive weight gain versus other interventions (general population)

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Weight gain (kg)4Mean Difference (IV, Fixed, 95% CI)Subtotals only

    1.1 Low-high exercise versus moderate-moderate exercise
150Mean Difference (IV, Fixed, 95% CI)-2.60 [-4.96, -0.24]

    1.2 Low-high exercise versus high-low exercise
151Mean Difference (IV, Fixed, 95% CI)-3.50 [-5.86, -1.14]

    1.3 High-low exercise versus moderate-moderate exercise
149Mean Difference (IV, Fixed, 95% CI)0.90 [-1.59, 3.39]

    1.4 Low glycaemic diet versus high glycaemic diet
162Mean Difference (IV, Fixed, 95% CI)1.40 [-0.62, 3.42]

    1.5 Dietary counselling plus probiotic versus dietary counselling
1171Mean Difference (IV, Fixed, 95% CI)0.20 [-1.21, 1.61]

    1.6 Low glycaemic diet plus exercise versus high glycaemic diet plus exercise
120Mean Difference (IV, Fixed, 95% CI)-8.20 [-11.27, -5.13]

 2 Caesarean delivery1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    2.1 Low glycaemic diet versus high glycaemic diet
162Risk Ratio (M-H, Fixed, 95% CI)1.25 [0.49, 3.18]

 3 Energy intake (kj)2Mean Difference (IV, Fixed, 95% CI)Subtotals only

    3.1 Low glycaemic diet versus high glycaemic diet
160Mean Difference (IV, Fixed, 95% CI)-280.0 [-1225.93, 665.93]

    3.2 Dietary counselling plus probiotic versus dietary counselling
1139Mean Difference (IV, Fixed, 95% CI)276.0 [-243.57, 795.57]

 4 Fibre intake (gm)2Mean Difference (IV, Fixed, 95% CI)Subtotals only

    4.1 Low glycaemic diet versus high glycaemic diet
160Mean Difference (IV, Fixed, 95% CI)-0.60 [-4.25, 3.05]

    4.2 Dietary counselling plus probiotic versus dietary counselling
1139Mean Difference (IV, Fixed, 95% CI)0.60 [-1.35, 2.55]

 5 Infant birthweight > 90th centile for gestational age1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    5.1 Low glycaemic diet versus high glycaemic diet
162Risk Ratio (M-H, Fixed, 95% CI)0.09 [0.01, 0.69]

 6 Infant birthweight <10th centile for gestational age1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    6.1 Low glycaemic diet versus high glycaemic diet
162Risk Ratio (M-H, Fixed, 95% CI)1.41 [0.25, 7.84]

 
Comparison 3. Interventions to prevent excessive weight gain versus standard care or routine care (high-risk groups)

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Excessive weight gain4Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    1.1 Behavioural counselling versus standard care
2226Risk Ratio (M-H, Fixed, 95% CI)1.19 [0.96, 1.47]

    1.2 Regular weight measurement versus standard care
184Risk Ratio (M-H, Fixed, 95% CI)0.92 [0.53, 1.62]

    1.3 Nutritional advice from brochure versus standard care
180Risk Ratio (M-H, Fixed, 95% CI)0.94 [0.59, 1.50]

    1.4 Behavioural counselling plus nutritional advice from a brochure versus standard care
185Risk Ratio (M-H, Fixed, 95% CI)0.83 [0.51, 1.34]

 2 Weight gain (kg)9Mean Difference (IV, Fixed, 95% CI)Subtotals only

    2.1 Behavioural counselling versus standard care
2212Mean Difference (IV, Fixed, 95% CI)0.60 [-1.30, 2.51]

    2.2 Regular weight measurement versus standard care
176Mean Difference (IV, Fixed, 95% CI)-0.08 [-2.00, 1.84]

    2.3 Nutritional advice from a brochure versus standard care
180Mean Difference (IV, Fixed, 95% CI)0.30 [-2.44, 3.04]

    2.4 Energy restriction counselling versus standard care (High BMI)
150Mean Difference (IV, Fixed, 95% CI)-6.70 [-10.31, -3.09]

    2.5 Energy restriction counselling versus standard care (high risk gestational diabetes)
1117Mean Difference (IV, Fixed, 95% CI)1.88 [-1.96, 5.72]

    2.6 Weight monitoring, continuity of care and counselling versus routine
1124Mean Difference (IV, Fixed, 95% CI)-6.80 [-8.63, -4.97]

    2.7 Diet and exercise counselling versus standard care
2147Mean Difference (IV, Fixed, 95% CI)-1.15 [-2.93, 0.63]

    2.8 Behavioural counselling plus nutritional advice from a brochure versus standard care
185Mean Difference (IV, Fixed, 95% CI)-0.80 [-3.89, 2.29]

 3 Low weight gain2Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    3.1 Behavioural counselling versus standard care
2226Risk Ratio (M-H, Fixed, 95% CI)0.80 [0.44, 1.47]

 4 Preterm birth3Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    4.1 Weight monitoring, continuity of care and counselling versus routine
1124Risk Ratio (M-H, Fixed, 95% CI)0.97 [0.06, 15.14]

    4.2 Behavioural counselling versus standard care
2216Risk Ratio (M-H, Fixed, 95% CI)1.20 [0.54, 2.64]

 5 Pre-eclampsia6Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    5.1 Behavioural counselling versus standard care
2216Risk Ratio (M-H, Fixed, 95% CI)1.38 [0.73, 2.60]

    5.2 Diet and exercise counselling versus standard care
193Risk Ratio (M-H, Fixed, 95% CI)1.24 [0.22, 7.05]

    5.3 Nutritional advice from a brochure versus standard care
180Risk Ratio (M-H, Fixed, 95% CI)0.39 [0.02, 9.20]

    5.4 Energy restriction counselling versus standard care (High BMI)
150Risk Ratio (M-H, Fixed, 95% CI)0.39 [0.02, 9.11]

    5.5 Energy restriction counselling versus standard care (high risk gestational diabetes)
1117Risk Ratio (M-H, Fixed, 95% CI)0.92 [0.48, 1.79]

    5.6 Behavioural counselling plus nutritional advice from a brochure versus standard care
185Risk Ratio (M-H, Fixed, 95% CI)0.51 [0.05, 5.44]

 6 Induction of labour2Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    6.1 Nutritional advice from a brochure versus standard care
180Risk Ratio (M-H, Fixed, 95% CI)0.83 [0.51, 1.36]

    6.2 Energy restriction counselling versus standard care
1117Risk Ratio (M-H, Fixed, 95% CI)1.08 [0.72, 1.63]

    6.3 Behavioural counselling plus nutritional advice from a brochure versus standard care
185Risk Ratio (M-H, Fixed, 95% CI)0.90 [0.60, 1.34]

 7 Caesarean delivery5Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    7.1 Behavioural counselling versus standard care
2216Risk Ratio (M-H, Fixed, 95% CI)0.76 [0.54, 1.05]

    7.2 Nutritional advice from a brochure versus standard care
180Risk Ratio (M-H, Fixed, 95% CI)1.49 [0.62, 3.62]

    7.3 Energy restriction counselling versus standard care (High BMI)
150Risk Ratio (M-H, Fixed, 95% CI)0.78 [0.14, 4.29]

    7.4 Energy restriction counselling versus standard care (high risk gestational diabetes)
1117Risk Ratio (M-H, Fixed, 95% CI)1.17 [0.74, 1.87]

    7.5 Behavioural counselling plus nutritional advice from a brochure versus standard care
185Risk Ratio (M-H, Fixed, 95% CI)0.65 [0.28, 1.52]

 8 Energy intake (kj)3Mean Difference (IV, Fixed, 95% CI)Subtotals only

    8.1 Nutritional advice from a brochure versus standard care
180Mean Difference (IV, Fixed, 95% CI)-1678.90 [-2381.74, -976.06]

    8.2 Energy restriction counselling versus standard care (high BMI)
143Mean Difference (IV, Fixed, 95% CI)-2057.0 [-3261.43, -852.57]

    8.3 Energy restriction counselling versus standard care (high risk gestational diabetes)
1117Mean Difference (IV, Fixed, 95% CI)-266.0 [-733.09, 201.09]

    8.4 Behavioural counselling plus nutritional advice from a brochure versus standard care
185Mean Difference (IV, Fixed, 95% CI)-1586.80 [-2417.92, -755.68]

 9 Fibre intake (gm)1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    9.1 Nutritional advice from a brochure versus standard care
180Mean Difference (IV, Fixed, 95% CI)2.0 [-0.64, 4.64]

 10 Physical activity score1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    10.1 Nutritional advice from a brochure versus standard care
180Mean Difference (IV, Fixed, 95% CI)0.32 [-0.11, 0.75]

    10.2 Behavioural counselling plus nutritional advice from a brochure versus standard care
185Mean Difference (IV, Fixed, 95% CI)0.34 [-0.19, 0.87]

 11 Physical activity (> 900 kcal/week expenditure) at 28 weeks1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    11.1 Exercise intervention versus standard care
141Risk Ratio (M-H, Fixed, 95% CI)1.73 [0.96, 3.10]

 12 Infant birthweight > 4000 gm5Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    12.1 Behavioural counselling versus standard care
2216Risk Ratio (M-H, Fixed, 95% CI)1.06 [0.54, 2.09]

    12.2 Nutritional advice from a brochure versus standard care
180Risk Ratio (M-H, Fixed, 95% CI)1.94 [0.50, 7.56]

    12.3 Energy restriction counselling versus standard care
1117Risk Ratio (M-H, Fixed, 95% CI)1.57 [0.62, 3.97]

    12.4 Diet and exercise counselling versus standard care
193Risk Ratio (M-H, Fixed, 95% CI)0.93 [0.39, 2.19]

    12.5 Behavioural counselling plus nutritional advice from a brochure versus standard care
185Risk Ratio (M-H, Fixed, 95% CI)0.61 [0.16, 2.41]

 13 Infant birthweight > 90th centile2Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    13.1 Energy restriction counselling versus standard care
1117Risk Ratio (M-H, Fixed, 95% CI)1.19 [0.64, 2.19]

    13.2 Diet and exercise counselling versus standard care
193Risk Ratio (M-H, Fixed, 95% CI)0.62 [0.23, 1.64]

 14 Infant birthweight < 2500 gm2Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    14.1 Behavioural counselling versus standard care
2216Risk Ratio (M-H, Fixed, 95% CI)0.99 [0.34, 2.95]

 15 Infant birthweight < 10th centile1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    15.1 Diet and exercise counselling versus standard care
193Risk Ratio (M-H, Fixed, 95% CI)1.65 [0.15, 17.54]

 16 Neonatal hypoglycaemia1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    16.1 Energy restriction counselling versus standard care
1110Risk Ratio (M-H, Fixed, 95% CI)0.73 [0.48, 1.13]

 17 Shoulder dystocia1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    17.1 Energy restriction counselling versus standard care
1117Risk Ratio (M-H, Fixed, 95% CI)0.12 [0.01, 2.33]

 18 Maternal weight retention (kg)2Mean Difference (IV, Fixed, 95% CI)Subtotals only

    18.1 Behavioural counselling versus standard care
135Mean Difference (IV, Fixed, 95% CI)3.30 [-0.88, 7.48]

    18.2 Energy restriction counselling versus standard care
135Mean Difference (IV, Fixed, 95% CI)-6.9 [-15.28, 1.48]

 19 Maternal weight gain above prepregnancy weight at 6 months postpartum1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    19.1 Behavioural counselling versus standard care
1177Risk Ratio (M-H, Fixed, 95% CI)0.90 [0.77, 1.05]

 
Comparison 4. Interventions to prevent excessive weight gain versus other interventions (high-risk groups)

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Excessive weight gain1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    1.1 Behavioural counselling plus nutritional advice from a brochure versus nutritional advice from a brochure
179Risk Ratio (M-H, Fixed, 95% CI)0.88 [0.53, 1.46]

 2 Weight gain (kg)4Mean Difference (IV, Fixed, 95% CI)Subtotals only

    2.1 Low glycaemic load versus low fat diets
138Mean Difference (IV, Fixed, 95% CI)-0.5 [-3.29, 2.29]

    2.2 Behavioural counselling plus nutritional advice from a brochure versus nutritional advice from a brochure
179Mean Difference (IV, Fixed, 95% CI)-1.10 [-4.30, 2.10]

    2.3 Aerobic exercise plus relaxation versus relaxation
172Mean Difference (IV, Fixed, 95% CI)-0.60 [-4.38, 3.18]

    2.4 Nutritionally monitored plus nutritional counselling versus nutritional counselling
1232Mean Difference (IV, Fixed, 95% CI)-9.07 [-10.90, -7.24]

 3 Preterm birth3Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    3.1 Aerobic exercise plus relaxation versus relaxation
172Risk Ratio (M-H, Fixed, 95% CI)1.89 [0.18, 19.95]

    3.2 Nutritionally monitored plus nutritional counselling versus nutritional counselling
1232Risk Ratio (M-H, Fixed, 95% CI)0.6 [0.15, 2.45]

    3.3 Low glycaemic load versus low fat diets
145Risk Ratio (M-H, Fixed, 95% CI)3.5 [0.42, 28.91]

 4 Pre-eclampsia2Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    4.1 Behavioural counselling plus nutritional advice from a brochure versus nutritional advice from a brochure
179Risk Ratio (M-H, Fixed, 95% CI)4.42 [0.22, 89.18]

    4.2 Nutritionally monitored plus nutritional counselling versus nutritional counselling
1232Risk Ratio (M-H, Fixed, 95% CI)0.64 [0.26, 1.58]

 5 Induction of labour2Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    5.1 Behavioural counselling plus nutritional advice from a brochure versus nutritional advice from a brochure
179Risk Ratio (M-H, Fixed, 95% CI)1.41 [0.88, 2.26]

    5.2 Nutritionally monitored plus nutritional counselling versus nutritional counselling
1232Risk Ratio (M-H, Fixed, 95% CI)0.71 [0.44, 1.15]

 6 Caesarean delivery3Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    6.1 Low glycaemic load versus low fat diets
145Risk Ratio (M-H, Fixed, 95% CI)0.58 [0.25, 1.37]

    6.2 Behavioural counselling plus nutritional advice from a brochure versus nutritional advice from a brochure
179Risk Ratio (M-H, Fixed, 95% CI)1.08 [0.50, 2.31]

    6.3 Nutritionally monitored plus nutritional counselling versus nutritional counselling
1232Risk Ratio (M-H, Fixed, 95% CI)1.10 [0.94, 1.27]

 7 Haemorrhage/infection postpartum1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    7.1 Nutritionally monitored plus nutritional counselling versus nutritional counselling
1232Risk Ratio (M-H, Fixed, 95% CI)0.73 [0.30, 1.74]

 8 Energy intake (kj)2Mean Difference (IV, Fixed, 95% CI)Subtotals only

    8.1 Low glycaemic diet versus high glycaemic diet
143Mean Difference (IV, Fixed, 95% CI)205.20 [-639.54, 1049.94]

    8.2 Behavioural counselling plus nutritional advice from a brochure versus nutritional advice from a brochure
179Mean Difference (IV, Fixed, 95% CI)92.10 [-644.14, 828.34]

 9 Fibre intake (gm)1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    9.1 Low glycaemic diet versus high glycaemic diet
143Mean Difference (IV, Fixed, 95% CI)2.70 [-0.62, 6.02]

 10 Physical activity score1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    10.1 Behavioral counselling plus nutritional advice from a brochure versus nutritional advice from a brochure
179Mean Difference (IV, Fixed, 95% CI)0.02 [-0.45, 0.49]

 11 Infant birthweight > 4000 gm3Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    11.1 Behavioural counselling plus nutritional advice from a brochure versus nutritional advice from a brochure
179Risk Ratio (M-H, Fixed, 95% CI)0.88 [0.28, 2.80]

    11.2 Nutritionally monitored plus nutritional counselling versus nutritional counselling
1232Risk Ratio (M-H, Fixed, 95% CI)2.25 [0.71, 7.10]

    11.3 Low glycaemic load versus low fat diets
145Risk Ratio (M-H, Fixed, 95% CI)1.75 [0.17, 17.95]

 12 Infant birthweight > 90th centile for gestational age2Risk Ratio (M-H, Random, 95% CI)Subtotals only

    12.1 Low glycaemic diet versus high glycaemic diet
163Risk Ratio (M-H, Random, 95% CI)1.03 [0.23, 4.73]

    12.2 Low glycaemic load versus low fat diets
145Risk Ratio (M-H, Random, 95% CI)0.58 [0.11, 3.16]

 13 Infant birthweight < 10th centile for gestational age1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    13.1 Low glycaemic diet versus high glycaemic diet
163Risk Ratio (M-H, Fixed, 95% CI)5.16 [0.26, 103.27]

 14 Maternal weight retention (kg)1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    14.1 Nutritionally monitored plus nutritional counselling versus nutritional counselling
1232Mean Difference (IV, Fixed, 95% CI)-13.71 [-14.48, -12.94]

 
Table 1. The original data and adjusted data of continuous data of the cluster-randomised trial (Luoto 2011)

OutcomeIntervention (Original data)Control (Original data)M1ICC2Design effect3Adjusted sample4 sizes



Cluster

number
Total numberx̄ ± SDCluster

number
Total numberx̄ ± SDInterventionControl

Maternal Weight gain721613.8±5.8717914.2±5.128.210.124.2750.6441.96

 1 M = average cluster size = ((total number of intervention + total number of control)/(cluster number of intervention + cluster number of control)
2 ICC = intraclass correlation; obtained from the reliable external source (Luoto 2010).
3 Design effect = 1 + (M-1)/ICC
4 Adjusted sample sizes = n / design effect
 
Table 2. The original data and adjusted data for dichotomous data of the cluster-randomised trial (Luoto 2011)

OutcomesIntervention (Original data)Control (Original data)M1ICC2Design effect3Intervention (Adjusted data)4Control(Adjusted data)4




Cluster

number
Total numbernCluster

number
Total numberntotal numberntotal numbern

Pre-eclampsia72161471791028.210.124.2750.643.2841.962.34

Birthweight > 4000 grams72163771793628.210.124.2750.648.6741.968.44

Infant birthweight > 90th centile72162671793428.210.124.2750.646.1041.967.97

Infant birthweight < the 10th centile7216107179528.210.124.2750.642.3441.961.17

 1 M = average cluster size = (total number of intervention + total number of control)/(cluster number of intervention + cluster number of control)
2 ICC = intraclass correlation; obtained from the reliable external source (Luoto 2010).
3 Design effect = 1 + (M-1)/ICC
4 Adjusted data = n / design effect
 
Table 3. Weight gain (computer-assisted self-interview plus nutrition education)

StudyTrimesterCASI plus nutrition educationCASI plus standard nutrition counsellingFP value




nMean weight gain (lb.)nMean weight gain (lb.)6.130.0000

Bechtel-Blackwell 20021173.20186.276.130.0000

22214.512414.882.330.056

32215.142412.293.440.0060

 
Table 4. Weight change during therapy (use of an appetite suppressant)

StudyDiethylpropion hydrochloridePlacebo


nDuration of therapy (weeks)Average weight change (lb.)nDuration of therapy (weeks)Average weight change (lb.)

Silverman 19712810.96.97910.98.78

Boileau 19685213.01.25312.97.0