Intervention Review

You have free access to this content

Kangaroo mother care to reduce morbidity and mortality in low birthweight infants

  1. Agustin Conde-Agudelo1,*,
  2. José M Belizán2,
  3. Jose Diaz-Rossello3

Editorial Group: Cochrane Neonatal Group

Published Online: 16 MAR 2011

Assessed as up-to-date: 30 JAN 2011

DOI: 10.1002/14651858.CD002771.pub2

How to Cite

Conde-Agudelo A, Belizán JM, Diaz-Rossello J. Kangaroo mother care to reduce morbidity and mortality in low birthweight infants. Cochrane Database of Systematic Reviews 2011, Issue 3. Art. No.: CD002771. DOI: 10.1002/14651858.CD002771.pub2.

Author Information

  1. 1

    Eunice Kennedy Shriver National Institute of Child Health and Human Development/National Institutes of Health/Department of Health and Human Services, Perinatology Research Branch, Detroit, Michigan, USA

  2. 2

    Institute for Clinical Effectiveness and Health Policy (IECS), Department of Mother and Child Health Research, Buenos Aires, Argentina

  3. 3

    University Hospital, Department of Neonatology, Montevideo, Uruguay

*Agustin Conde-Agudelo, Perinatology Research Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development/National Institutes of Health/Department of Health and Human Services, Detroit, Michigan, USA. condeagu@hotmail.com.

Publication History

  1. Publication Status: New search for studies and content updated (conclusions changed)
  2. Published Online: 16 MAR 2011

SEARCH

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

MethodsRandomized controlled trial carried out in the neonatal section of a teaching hospital in India.


Participants114 infants. Inclusion criteria: hemodynamically stable infants delivered by vaginal route with birthweight between 1200 and 1800 g.

Infant's stabilization status at trial entry: stabilized

Exclusion criteria: neonates delivered by cesarean section, major life threatening congenital malformations, severe perinatal complications, and parental refusal for KMC intervention.

81% of LBW infants met eligibility criteria. Mean age and weight at recruitment was 4.7 ± 2.9 and 4.8 ± 2.4 days, and 1607 ± 211 and 1615 ± 179 g for KMC and control infants, respectively.


Interventions(1) KMC group (n = 58): SSC between the mother's breasts in an upright position. Infants were dressed with a cap, socks, and diaper and supported in bottom with a sling/binder. The duration of KMC during hospital stay was 6.3 ± 1.5 hours (range, 4-12) per day, and was given for a period of 25.7 ± 6.9 (range, 15-43) days after enrollment in the study.

(2) control group (n = 56): infants were kept in radiant warmers or open cots in warm rooms.

In both groups, mothers were allowed to handle their babies at any hour of the day and breast feed them by nasogastric tube, paladai or directly. Babies in both groups were provided with vitamins and mineral supplementation.


OutcomesDuration of hospital stay, weight gain, head circumference, length, exclusive breastfeeding, nosocomial sepsis, hypothermia, mild/moderate infection, severe infection, and mortality.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate sequence generation?YesBlock randomization technique.

Allocation concealment?UnclearNo information provided.

Blinding?
All outcomes
NoBlinding of participants: no/unfeasible; blinding of clinical staff: no/unfeasible; blinding of outcome assessors: unclear.

Incomplete outcome data addressed?
All outcomes
Yes10 infants (8.8%) were lost at 40 weeks' corrected gestational age follow up (KMC 4, control 6), 21 (18.4%) were lost at 3 months' corrected age (KMC 10, control 11), and 39 (34.2%) were lost at 6 months' corrected age (KMC 19, control 20).

Free of selective reporting?NoNon-significant results such as infant mortality (weight, length, and head circumference at discharge and follow up (secondary outcomes listed in Methods) were mentioned but not reported adequately.

Free of other bias?NoUse of blocked randomization which could make it possible to predict future assignments in an unblinded trial when the assignments are revealed subsequent to the person recruiting into the trial.

Blaymore Bier 1996

MethodsRandomized controlled trial carried out in the special care nursery of a hospital in Providence, United States.


Participants50 infants. Inclusion criteria: medically stable infants from singleton or multiple pregnancy with birth weight <1500 g and whose mothers planned to breast-feed. The infants were no longer ventilator dependent and without chest tubes, and they no longer required continuous positive airway pressure when the study was begun.

Infant's stabilization status at trial entry: stabilized

Exclusion criteria: mother's positive history of illicit drug use, mental illness, human immunodeficiency virus (HIV) infection, or receiving any medications contraindicative to breast-feeding. In addition, any infants who had a positive toxicologic screen for cocaine or other illicit drugs or were showing drug withdrawal symptoms at birth were excluded.

No data on percentage of LBW infants that met eligibility criteria. Mean age and weight at recruitment was 29 and 30 days, and 993 ± 275 and 942 ± 322 g for KMC and control infants, respectively.


Interventions(1) KMC group (n = 25): SSC involved the infant clothed in only a diaper and hat, held upright between the mother's breasts, with the mother and infant covered with a blanket.

(2) control group (n = 25): standard contact involved a fully clothed infant wrapped in a blanket and held cradled in his or her mother's arms.

During the study, the mother-infant dyad was observed participating in SSC or standard contact once each weekday until bottle and breast-feedings were initiated or for a maximum of 10 days.The duration of the SSC and standard contact sessions was 10 minutes per day.


OutcomesBreastfeeding and physiological data.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate sequence generation?YesShuffling envelopes.

Allocation concealment?UnclearNo information provided.

Blinding?
All outcomes
NoBlinding of participants: no/unfeasible; blinding of clinical staff: no/unfeasible; blinding of outcome assessors: unclear.

Incomplete outcome data addressed?
All outcomes
Yes21 mothers of 25 infants were allocated to KMC group, and 20 mothers of 25 infants were allocated to standard contact group. One mother in the KMC group was lost to follow up after discharge. Two mothers in the control group were excluded because they wanted to participate in KMC group.

Free of selective reporting?Yes

Free of other bias?YesOther biases have not been identified.

Boo 2007

MethodsRandomized controlled trial carried out in the NICU of a tertiary teaching hospital in Malaysia.


Participants128 infants. Inclusion criteria: very low birthweight infants (<1501 g) in stable condition, nursed in a closed incubator, not requiring ventilatory support other than nasal continuous positive airway pressure, able to tolerate enteral feeds of at least 50% of the required fluid volume, and having at least one parent or guardian who was willing to participate in the study.

Infant's stabilization status at trial entry: stabilized

Exclusion criteria included lethal or major malformations, severe perinatal asphyxia, with evidence of hypoxic ischemic encephalopathy, transfer to another hospital, abandoned by parents or parental refusal to participate.

43% of LBW infants met eligibility criteria. Median age and weight at recruitment was 24.5 and 20.5 days, and 1514 and 1492 g for KMC and control infants, respectively.


Interventions(1) KMC group (n = 65): parent held the infant prone on their naked chest, in a semi-upright position and between his/her breasts. Infants wore only a nappy and a bonnet. Both parent and infant were covered with a thermal blanket. Median duration of SSC was 1 hour per day with a mean total duration of 12.7 ± 5.0 days.

(2) control group (n = 63): infants were not exposed to SSC while in the NICU. All mothers were encouraged to breast feed their infants.


OutcomesDuration of hospital stay, weight gain, weekly increase in head circumference, breastfeeding rate at discharge, sepsis, and mortality at discharge.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate sequence generation?YesShuffling envelopes.

Allocation concealment?YesNumbered sealed envelopes.

Blinding?
All outcomes
NoBlinding of participants: no/unfeasible; blinding of clinical staff: no/unfeasible; blinding of outcome assessors: unclear.

Incomplete outcome data addressed?
All outcomes
No8 infants in the KMC group (12.3%) were excluded because SSC sessions were carried out on less than 50% of hospital stay days after recruitment.

Free of selective reporting?Yes

Free of other bias?YesOther biases have not been identified.

Cattaneo 1998

MethodsMulticentre randomized controlled trial carried out in 3 tertiary hospitals in Addis Ababa (Ethiopia), Yogyakarta (Indonesia), and Merida (Mexico).


Participants285 infants. Inclusion criteria: infants with birthweight between 1000 and 1999 g without gestational age limits, no dependency on oxygen, and/or i.v. fluids, ability (at least partial) to feed, no visible major malformation, and mother present and willing to collaborate.

Infant's stabilization status at trial entry: stabilized

Exclusion criteria were not described.

44% of LBW infants met eligibility criteria. Median age (range) and mean weight (SD) at recruitment was 10 (1-74) and 8 (1-40) days, and 1584 (223) and 1574 (251) g for KMC and control infants, respectively.


Interventions(1) KMC group (n = 149): infants were kept in close and continuous SSC, between the mother's breasts, naked except for a diaper and a hat covered across their backs with their mother's clothes, day and night, for an average of about 20 hours/day, including when the mother was asleep. The mother was occasionally replaced, for few hours, by another person usually the father or a member of the family. For short absences of the mother (<1 hour) the baby was left on the mother's bed, covered by a blanket.

(2) Control group (n = 136): infants were kept in a warm room in Addis Ababa, with open cribs and the possibility of rewarming in a bulb-heated cot, and in incubators in the other two hospitals. SSC with their mothers was not allowed.


OutcomesSevere illness, hypothermia, hyperthermia, breastfeeding, weight gain, neonatal death, acceptability to health workers, acceptability to mothers, and costs.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate sequence generation?YesRandom number table.

Allocation concealment?UnclearNo information provided.

Blinding?
All outcomes
NoBlinding of participants: no/unfeasible; blinding of clinical staff: no/unfeasible; blinding of outcome assessors: Unclear.

Incomplete outcome data addressed?
All outcomes
UnclearIt was not reported the number of infants lost to follow up or excluded after randomization.

Free of selective reporting?Yes

Free of other bias?UnclearIn Indonesia, randomization was carried out in blocks of six and stratifying by weight which could make it possible to predict future assignments in an unblinded trial when the assignments are revealed subsequent to the person recruiting into the trial.

Charpak 1997

MethodsRandomized controlled trial carried out in a single tertiary centre in Bogotá, Colombia.


Participants777 infants. Inclusion criteria: Infants from singleton or multiple pregnancy with birth weights <2001 g, with a mother or a relative able to understand and willing to follow the general program instructions.

Infant's stabilization status at trial entry: stabilized

Exclusion criteria: being referred to another institution, plans to leave Bogota in the near future, life-threatening or major malformations, early-detected major conditions arising from perinatal problems, and parental or family refusal to comply with the follow up program or, for those assigned to the KMC group, refusal to comply with the specifics of the intervention.

72% of LBW infants met eligibility criteria. Median age (range) and mean weight (SD) at recruitment was 4 (1-60) and 3 (1-55) days, and 1678 (226) and 1715 (228) g for KMC and control infants, respectively.


Interventions(1) KMC group (n = 396): infants were kept 24 hours a day in a strict upright position, in SSC firmly attached to the mother's chest. Infants were breast fed regularly, although premature formula supplements were administered if necessary. Infants were discharged as soon as they overcame major adaptations to extrauterine life, received proper treatment for infection or concomitant condition, sucked and swallowed properly, and achieved a positive weight gain.

(2) Control group (n = 381): infants were kept in an incubator until they were able to regulate temperature and were thriving. The parent's access to their babies was severely restricted.


Outcomes1. At 40-41 weeks' corrected gestational age: mortality, infant growth, length of hospital stay, infection, breastfeeding, and mother-infant attachment.

2. At 12 months corrected age: neurodevelopmental disability, and social and home environment.


NotesInformed consent was not asked to parents of infants allocated to the control group. Additional data provided by Dr Nathalie Charpak.


Risk of bias

ItemAuthors' judgementDescription

Adequate sequence generation?YesRandom number table.

Allocation concealment?UnclearThe person managing allocation was aware of weight at birth and whether the infant was a twin or triplet.

Blinding?
All outcomes
NoBlinding of participants: no/unfeasible; blinding of clinical staff: no/unfeasible; blinding of outcome assessors: unclear.

Incomplete outcome data addressed?
All outcomes
Yes31 infants (4%) (KMC 14, control 17) were excluded after randomization due to pre-existing neurologic impairment, or fetal intrauterine infection not detected at time of randomization. follow up at 40 to 41 weeks' corrected gestational age was incomplete for 67 (8.6%) survivor infants (KMC 33, control 34), but mortality data were available in 30 of these, giving mortality data for 364 vs 345.

Free of selective reporting?Yes

Free of other bias?NoUse of blocked randomization which could make it possible to predict future assignments in an unblinded trial when the assignments are revealed subsequent to the person recruiting into the trial.

Gathwala 2008

MethodsRandomized controlled trial carried out in a single centre in Rohtak, India.


Participants110 infants. Inclusion criteria: Infants with birthweight ≤1800 g, stable cardiopulmonary status, Apgar score ≥7 at 1 and 5 minute, tolerating enteral feeds, and maintaining temperature.

Infant's stabilization status at trial entry: stabilized

Exclusion criteria: infants sick, unstable, or with major congenital malformations, or whose mothers were unwell and unable to come or refused consent.

No data on percentage of LBW infants that met eligibility criteria. Mean age at recruitment was 1.7 ± 0.5 days. Mean birthweight was 1690 ± 110 and 1690 ± 120 g for KMC and control infants, respectively.


Interventions(1) KMC group (n = 50): Infants were kept in SSC, between the mother's breasts, naked except for a cap and nappy, for at least 6 hours per day. The duration of KMC in the first month was 10.2 ± 1.5 hours per day, in the second month was 10.0 ± 1.6, and in the third month was 9.0 ± 1.4. The gown covered the baby's trunk and extremities but not the head. The KMC was given for a minimum of one hour at a stretch and continued for as long as it was comfortable to baby and mother. When not receiving KMC the infants received standard care under a warmer or incubator.

(2) Control group (n = 50): infants were kept in a warmer or incubator. Mothers were allowed to visit their babies and touch and handle them.

Babies in the KMC group continued to receive KMC after they were shifted to the mother in the ward. Babies in the control group were also shifted to the mother in her bed but did not receive KMC.


OutcomesAttachment between mother and infant at 3 months follow up, duration of hospital stay, breastfeeding, and weight, length and circumference head gain.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate sequence generation?YesRandom number table.

Allocation concealment?UnclearNo information provided.

Blinding?
All outcomes
NoBlinding of participants: no/unfeasible; blinding of clinical staff: no/unfeasible; blinding of outcome assessors: unclear.

Incomplete outcome data addressed?
All outcomes
Unclear10 infants (9.1%) were lost to follow up. It was not reported the number of infants lost to follow up in each intervention group. Out of the remaining 100, 50 received KMC and 50 received standard care.

Free of selective reporting?Yes

Free of other bias?YesOther biases have not been identified.

Kadam 2005

MethodsRandomized controlled trial carried out in a tertiary care centre in Mumbai, India.


Participants89 infants. Inclusion criteria: Infants with birthweight ≤1800 g, stable cardiopulmonary status, Apgar score ≥7 at 5 minute, and on feeds (breast feeds or spoon wati feeds with expressed breast milk).

Infant's stabilization status at trial entry: stabilized

Exclusion criteria: infants sick and unstable, or with major congenital malformations, or whose parents refused consent.

No data on percentage of LBW infants that met eligibility criteria. The mean age (range) at enrolment was 3.2 (1-8) days for both groups. Mean birthweight was 1467 ± 228 and 1461 ± 217 g for KMC and control infants, respectively.


Interventions(1) KMC group (n = 44): infants were placed on mother's chest in between the breasts in vertical position supported by a cloth dupatta, with mothers seating in a semi-reclining position, for a mean of 9.8 ± 3.7 hours per day. In case of any problem the baby was transferred to conventional care and after stabilization was transferred back to KMC, which was continued until discharge

(2) Control group (n = 45): infants were kept in radiant warmers. More than 95% of babies in both groups received exclusive breastfeeding and the remaining were supplemented by banked human milk. Mothers in both groups were allowed to enter and handle the babies at any hour of the day, change diapers, and breast feed the babies.


OutcomesMortality, morbidity (hypothermia, hyperthermia, sepsis, apnea), onset of breastfeeding, duration of hospital stay, and weight at discharge.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate sequence generation?YesSealed envelope method.

Allocation concealment?YesSealed envelopes.

Blinding?
All outcomes
NoBlinding of participants: no/unfeasible; blinding of clinical staff: no/unfeasible; blinding of outcome assessors: unclear.

Incomplete outcome data addressed?
All outcomes
YesThere were no infants lost to follow up.

Free of selective reporting?Yes

Free of other bias?YesOther biases have not been identified.

Nagai 2010

MethodsRandomized controlled trial carried out in a referral hospital in Mahajanga, Madagascar.


Participants73 infants. Inclusion criteria: infants with birthweight <2500 g, less than 24 hours post birth, no serious malformation, relatively stable clinical condition (oxygen saturation ≥95%; heart rate >100 beats/min; respiratory rate <60 times/min; capillary refilling time <3 sec), and healthy mother and/or other family members willing to practice KMC.

Infant's stabilization status at trial entry: relatively stabilized

Exclusion criteria: prolonged apnea (>20 sec) and intravenous infusion

52% of LBW infants met eligibility criteria. Mean age and weight at recruitment was 19.8 ± 14.3 and 33.0 ± 13.2 hours, and 2075 ± 272 and 2078 ± 292 g for early onset KMC and late onset KMC infants, respectively.


Interventions(1) Early KMC group (n = 37): infants were kept in direct and continuous SSC (without any underwear, except for a diaper, a warm hat, and socks for the baby) for as long as possible. SSC was begun as soon as possible, within 24 hours post birth.

(2) Late KMC group (n = 36): initially, infants were kept in incubator or radiant warmer. Later, infants were covered with cotton cloth and laid beside the mothers. KMC was begun after complete stabilization (generally after 24 hours post birth) of infant.

After initiating KMC, all participants were encouraged to continue KMC for as long as possible during hospitalization and after discharge. Other family members assisted the mother occasionally in performing continuous KMC.


OutcomesPrimary outcomes: mortality at 4 weeks of age.

Secondary outcomes: morbidities (severe infection treated with antibiotics, high fever diagnosed as malaria, and both anorexia and hypoactivity with subsequent re-hospitalization) and adverse events (hypothermia, hyperthermia, bradycardia and/or tachycardia, and prolonged apnea) at 4 weeks of age, body weight changes from birth to 24 hours, 48 hours, 14 days, and 28 days post birth, duration of hospital stay, discharge within 7 days post birth, and feeding methods from birth to 24 and 48 hours.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate sequence generation?YesMinimization method by software "minim".

Allocation concealment?YesSoftware automatically provided the random allocation for each participant.

Blinding?
All outcomes
YesBlinding of participants: no/unfeasible; blinding of clinical staff: no/unfeasible; blinding of outcome assessors: a neonatologist who was masked to the allocation of participants and who did not have any contact with participants, determined the classification of morbidities based on the interview records and medical charts.

Incomplete outcome data addressed?
All outcomes
YesThere were no infants lost to follow up.

Free of selective reporting?Yes

Free of other bias?YesOther biases have not been identified.

Neu 2010

MethodsRandomized controlled trial carried out in Aurora (Colorado), United States.


Participants60 infants. Inclusion criteria: healthy infants with gestational age between 32 and 34 weeks, oxygen requirement <½ liter O2 per nasal cannula, infant without umbilical lines, intraventricular hemorrhage, physical anomalies, or anticipated major surgery, mother fluent in English or Spanish without recorded or stated illicit drug use, or diagnosis of serious chronic illness.

Infant's stabilization status at trial entry: stabilized

Exclusion criteria were not described.

Approximately 60% of mothers who were approached declined to be in the study. Mean age at recruitment and birthweight was 15.0 ± 6.7 and 15.0 ± 4.9 days, and 1990 ± 450 and 1880 ± 340 g for KMC and control infants, respectively.


InterventionsAn 8-week home intervention encouraged daily 1-hour, uninterrupted holding with either KMC (baby in SSC on mother's chest) (n = 31) or mother's arms (baby wrapped in blanket and held in mother's arms) (n = 29). In both conditions, weekly home visits by and experienced Registered Nurse included encouragement to hold the infant, emotional support, and information about infant behavior and development. Other control group received brief social visits, had no holding constraints and participated in all assessments. In the meta-analysis, we excluded results from this last control group.


OutcomesMother-infant interaction at six months follow up and infant vitality during the neutral-face period of the Still-Face Procedure.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate sequence generation?YesComputer random number generator.

Allocation concealment?YesOpaque sealed envelopes.

Blinding?
All outcomes
UnclearFour researchers assessed outcome measures. Two outcome assessors were blinded to the hypotheses of the study but not to group assignment of the mother-infant dyads. The other two researchers were blinded to group assignment and hypotheses.

Incomplete outcome data addressed?
All outcomes
Yes87 infants were randomized, 31 to KMC group, 29 to traditional holding and 36 to control group. At 6 months of age, 8 infants (9.2%) were lost to follow up and 14 (16.1%) were excluded (8 withdrawn by maternal reasons and 6 due to technical problems videotaping).

Free of selective reporting?Yes

Free of other bias?YesOther biases have not been identified.

Ramanathan 2001

MethodsRandomized controlled trial carried out in a single centre in New Delhi, India.


Participants28 infants. Inclusion criteria: Infants with birthweight <1500 g, stable cardiopulmonary status, tolerating enteral feeds and maintaining temperature in the thermoneutral environment.

Infant's stabilization status at trial entry: stabilized

Exclusion criteria: infants whose mothers were unable to come to the nursery because of illness or disability.

No data on percentage of LBW infants that met eligibility criteria. The median age at initiation of KMC was 11.8 days. Mean birthweight was 1219 ± 186 and 1271 ± 170 g for KMC and control infants, respectively.


Interventions(1) KMC group (n = 14): infants were kept between the mother's breasts, for at least 4 hours per day in not more than 3 sittings. The gown covered the baby's trunk and extremities but not the head. When not receiving KMC the infants received standard care under a warmer or incubator.

(2) Control group (n = 14): infants were kept in a warmer or incubator. Mothers were allowed to visit their babies and touch and handle them.

Breastfeeding guidelines were followed for both groups and lactation counseling was emphasized to ensure breast milk feeding.


OutcomesWeight gain, breastfeeding, and duration of hospital.


NotesInfants in the KMC group required positive pressure ventilation, continuous positive airway pressure, and oxygen therapy for more duration of time than the infants in the control group indicating that these infants were sicker before enrollment.


Risk of bias

ItemAuthors' judgementDescription

Adequate sequence generation?YesRandom number table.

Allocation concealment?UnclearNo information provided.

Blinding?
All outcomes
NoBlinding of participants: no/unfeasible; blinding of clinical staff: no/unfeasible; blinding of outcome assessors: unclear.

Incomplete outcome data addressed?
All outcomes
YesThere were no infants lost to follow up.

Free of selective reporting?UnclearDespite neonatal complications prospectively recorded, they were not reported.

Free of other bias?YesOther biases have not been identified.

Roberts 2000

MethodsRandomized controlled trial carried out in two neonatal nurseries in Darwin, Australia.


Participants30 infants. Inclusion criteria: premature or small for gestational age infants born at 30 or more weeks gestation or corrected age, with a five-minute Apgar of at least 5, medically stable, without congenital abnormalities or central nervous system impairment. Infants could have nasal continuous positive airway pressure in place or a nasal cannula. No data on percentage of LBW infants that met eligibility criteria.

Infant's stabilization status at trial entry: stabilized

Exclusion criteria: phototherapy within the previous 24 hours, resuscitated infants, and mothers with a history of drug use.

No data on percentage of LBW infants that met eligibility criteria. Mean age and weight at recruitment was 31.5 ± 2.7 days and 1690 ± 333 g, respectively.


Interventions(1) KMC group (n = 16): infants were dressed only in a diaper, with addition of a bonnet for smaller infants. They were then placed on the mother's skin and covered with a light blanket. Mean duration of KMC was 1.6 ± 0.9 hours per day, five days a week.

(2) control group (n = 14): infants were swaddled in infant clothing and a light blanket. They had contact with the mother only through normal clothing.

Breastfeeding was permitted as desired in both groups.


OutcomesWeight gain, length of stay in hospital, temperature, and breastfeeding.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate sequence generation?YesShuffling envelopes.

Allocation concealment?YesNumbered envelopes.

Blinding?
All outcomes
NoBlinding of participants: no/unfeasible; blinding of clinical staff: no/unfeasible; blinding of outcome assessors: unclear.

Incomplete outcome data addressed?
All outcomes
YesThere were no infants lost to follow up.

Free of selective reporting?Yes

Free of other bias?YesOther biases have not been identified.

Rojas 2003

MethodsRandomized controlled trial carried out in a tertiary NICU at Yale New Haven Hospital in Connecticut, United States.


Participants60 infants. Inclusion criteria: very low birthweight infants (<1501 g) with gestational age ≤32 weeks, with minimal ventilatory support or extubated on nasal continuous positive airway pressure or nasal canula, and hemodynamic stability. 19% of LBW infants met eligibility criteria.

Infant's stabilization status at trial entry: stabilized

Exclusion criteria: mother's age <18 years, or if there was a history of illicit drug use during pregnancy, clinical evidence of perinatal asphyxia, potential transfer within the first month after birth, presence of a major congenital anomaly, planned adoption, Grade III or IV intraventricular hemorrhage, fetal growth restriction, or suspected sepsis.

19% of LBW infants met eligibility criteria. Mean age and weight at trial entry was 19 days, and 1021 ± 268 and 1002 ± 219 g for KMC and control infants, respectively.


Interventions(1) KMC group (n = 33): infants were held in a prone semi-upright position at approximately a 45° angle, in direct SSC with the parent's chest.The infants wore only a diaper, and their backs were covered with a blanket. Mean duration of KMC was 1.3 ± 0.7 hours per day for an average of 15 ± 16 days.

(2) control group (n = 27): parents removed their infants from the incubator and held them in their arms in supine position with eye-to-eye contact. The infant wore diapers and T-shirts and were wrapped in a blanket.


OutcomesMortality at discharge, sepsis, necrotizing enterocolitis, intraventricular hemorrhage, weight, head circumference, and length at discharge, rate of weight gain and head circumference growth, total weight gain and head circumference growth, breastfeeding at discharge, and hospital stay


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate sequence generation?YesRandom number table.

Allocation concealment?YesNumbered, sealed, opaque envelopes.

Blinding?
All outcomes
NoBlinding of participants: no/unfeasible; blinding of clinical staff: no/unfeasible; blinding of outcome assessors: no.

Incomplete outcome data addressed?
All outcomes
YesThere were no infants lost to follow up.

Free of selective reporting?Yes

Free of other bias?YesOther biases have not been identified.

Sloan 1994

MethodsRandomized controlled trial carried out in a single centre in Quito, Ecuador.


Participants300 infants. Inclusion criteria: singleton infants weighing less than 2000 g, with no serious congenital abnormalities or respiratory, metabolic, or infectious disease. Infants had to be stabilized for the 24 h before enrolment (temperature between 36.5 and 37.0 ºC); acceptable tolerance of food; and stable weight.

Infant's stabilization status at trial entry: stabilized

Exclusion criteria were not described.

53% of LBW infants met eligibility criteria. Mean age and weight at recruitment was 13.0 ± 10.5 days, and 1618 ± 317 g, respectively.


Interventions(1) KMC group (n = 140): infants were kept in an upright position, in SSC contact (diapers allowed) against the mother's breasts and had frequent breastfeeding. SSC was reported by 68% of mothers at 1 month, 47% at 1.5 months, 20% at 2 months, and 7% at 3 months follow up.

(2) Control group (n = 160): infants stayed in an incubator or thermal crib and were breast fed at scheduled times.


OutcomesSevere illnesses (lower respiratory tract disorders, apnea, aspiration, pneumonia, septicemia, general infections), moderate illness (urinary infections), mild illnesses (upper respiratory tract disorders, dermatitis, jaundice, hip displacement), diarrhea, infant growth (weight, length, upper arm and head circumference), duration of hospital stay, re-admission, and costs of care.


NotesAdditional data provided by Dr Nancy L. Sloan.


Risk of bias

ItemAuthors' judgementDescription

Adequate sequence generation?YesRandom number table.

Allocation concealment?UnclearNo information provided.

Blinding?
All outcomes
NoBlinding of participants: no/unfeasible; blinding of clinical staff: no/unfeasible; blinding of outcome assessors: unclear.

Incomplete outcome data addressed?
All outcomes
YesOutcome data were reported for 131 KMC infants and 152 controls. 17 infants (5.7%) lost to follow up (KMC 9, control 8); no exclusions.

Free of selective reporting?UnclearSecondary outcomes such as Infant growth indices at follow up and costs of care were mentioned but not reported adequately.

Free of other bias?NoThe trial was stopped early because a highly significant difference (p<0.02 at 2 months, p<0.005 at 6 months) in severe morbidity arose. No information about whether this was a planned interim analysis.

Suman 2008

MethodsRandomized controlled trial carried out in a single centre in Mumbai, India.


Participants220 infants. Inclusion criteria: singleton infants with birthweight less than 2000 g. 63% of LBW infants met eligibility criteria.

Infant's stabilization status at trial entry: stabilized

Exclusion criteria: infants critically ill requiring ventilatory or inotropic support, or with chromosomal and life threatening congenital anomalies, or requiring transfer, or whose mothers were critically ill, or unable to comply with the follow up schedule.

Mean age and weight at recruitment was 3.7 ± 2.8 and 2.3 ± 1.9 days, and 1608 ± 278 and 1691 ± 273 g for KMC and control infants, respectively.


Interventions(1) KMC group (n = 108): infants were kept in SSC using a specially tailored "kangaroo bag" made of soft flannel cloth on the reclining cot in the semi-upright position with the help of pillows. Mothers were encouraged to keep the baby in KMC as long as possible during the day and night with a minimum period of one to two hours at a time. When the baby was not in KMC, the baby was placed either under a servo controlled radiant warmer or in a cradle under hot lamp adequately clothed and covered. Mean duration of KMC was 13.5 hours per day with a mean total duration of 33.8 ± 15.1 days.

(2) Control group (n = 112): infants were managed under a servo controlled radiant warmer or in a cradle under hot lamp in NICU adequately clothed and covered.

All babies were exclusively breast fed. Infants who developed a life threatening event or required phototherapy were temporarily withdrawn from the KMC group.


OutcomesInfant growth (weight, length, head, chest, and mid-arm circumference, and foot length), mortality, morbidity (hypothermia, hyperthermia, hypoglycemia, sepsis, apnea in <1500 g, other minor illness), and duration of hospital stay.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate sequence generation?YesSimple randomization.

Allocation concealment?YesSealed envelopes.

Blinding?
All outcomes
NoBlinding of participants: no/unfeasible; blinding of clinical staff: no/unfeasible; blinding of outcome assessors: no.

Incomplete outcome data addressed?
All outcomes
No49 infants (22.3%) were lost to follow up (KMC 11[10.2%], control 38 [33.9%]); 14 babies (6.4%) were excluded (KMC 5, control 9) because they did not receive assigned care.

Free of selective reporting?Yes

Free of other bias?UnclearThe groups were different at baseline in two important variables: (1) weight at enrolment (1608 ± 278 and 1691 ± 273 g for KMC and control infants, respectively; P=0.03) and (2) age at enrolment (3.7 ± 2.8 and 2.3 ± 1.9 days for KMC and control infants, respectively; P<0.01).

Whitelaw 1988

MethodsRandomized controlled trial carried out in a neonatal unit of a single centre in London, United Kinfdom.


Participants71 infants. Inclusion criteria: infants from singleton or twin pregnancy with weight less than 1500 g, stable breathing with no oxygen requirement, and a least one parent speaking fluent English. Stable infants were not excluded if they had congenital malformations such as hydronephrosis or scoliosis, nor if they had intracranial lesions such as periventricular leukomalacia or ventricular dilatation.

Infant's stabilization status at trial entry: stabilized

Exclusion criteria were not described.

50% of LBW infants met eligibility criteria. The mean (range) age at enrolment was 16 (1-66) days. Mean birthweight was 1152 ± 220 and 1135 ± 263 g for KMC and control infants, respectively.


Interventions(1) KMC group (n = 35): infants were kept in an upright position, in SSC between the mother's breasts with a cardiac or respiration monitor attached. Mean (range) duration of KMC was 0.6 (0-1.5) hours per day.

(2) Control group (n = 36): mother was encouraged to visit as much as she liked and helped to take her baby out of the incubator for a cuddle. However, baby and mother remained clothed. Care was taken that the normal contact group would have no less attention from the nursing staff.


OutcomesBreastfeeding and infant's behaviour at 6 months of age, and mother's feelings about the infant at discharge and 6 months of age.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate sequence generation?YesShuffling envelopes.

Allocation concealment?YesSequentially numbered, sealed, opaque envelopes.

Blinding?
All outcomes
NoBlinding of participants: no/unfeasible; blinding of clinical staff: no/unfeasible; blinding of outcome assessors: no.

Incomplete outcome data addressed?
All outcomes
YesThere were no infants lost to follow up.

Free of selective reporting?UnclearNon-significant results such as mother's feelings about the infant at discharge and at 6 months follow up, were mentioned but not reported adequately.

Free of other bias?YesOther biases have not been identified.

Worku 2005

MethodsRandomized controlled trial carried out in a neonatal unit of a single centre in Addis Ababa, Ethiopia.


Participants123 infants. Infants with birthweight less than 2000 g, singletons unless one of the twins died, no major congenital malformation, and mother healthy and willing to participate.

Infant's stabilization status at trial entry: non stabilized

Exclusion criteria were not described.

48% of LBW infants met eligibility criteria. The mean age at enrolment and birthweight was 10.0 and 9.8 hours, and 1515 and 1472 g for KMC and control infants, respectively.


Interventions(1) Early KMC group (n = 62): infants were kept in continuous SSC with their mother beginning immediately after birth or within the first 24 hours of life (before stabilization). The mother kept her newborn infant between the breasts, in close contact with her body and covered with her clothes day and night. Breastfeeding was the standard feeding method. However, the mother could also feed her baby with formula milk using tube or cup when needed. KMC could be combined with a heated room during low environmental temperatures.

(2) Control group (n = 61): infants were kept in a heated room overhead lamp warmers with oxygen therapy, and breast, tube, cup, or mixed feeding.

The two methods of care were applied and continued until the baby was considered stabilized (stable temperature, stabilized cardiovascular status, satisfactory ability to suck, and good general condition) and then both groups of babies were transferred to the ward routine Kangaroo care service. KMC was continued at home after discharge in both groups.


OutcomesDeath, serious illness (sepsis, diarrhea, pneumonia, aspiration, pneumonia), and mothers' feeling towards the method of care.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate sequence generation?YesRandom number table.

Allocation concealment?UnclearNo information provided.

Blinding?
All outcomes
NoBlinding of participants: no/unfeasible; blinding of clinical staff: no/unfeasible; blinding of outcome assessors: no.

Incomplete outcome data addressed?
All outcomes
UnclearThere was no information on infants lost to follow up or exclusions.

Free of selective reporting?NoThe great majority of outcomes listed in the Methods section of the article, such as weight gain, mild/moderate and severe illness, sepsis, diarrhea, pneumonia, aspiration, and mother's feelings, were collected but not reported.

Free of other bias?YesOther biases have not been identified.

 
Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion

Ahn 2010Non-randomized trial

Anderson 2003The study compared SSC (N=48) and standard care (N=43) in preterm infants born at 32-36 weeks' gestation with birth weight between 1300 and 3000 g. No data on daily duration of KMC. Study did not report results for clinical outcomes.

Arandia 1993Non-randomized trial

Bergman 1994Non-randomized trial

Bergman 2004The study compared SSC (N=21) from birth and standard care (N=14) in LBW infants. The study period was 6 hours. The study only reported results for physiological parameters. Newborns receiving SSC from birth were significantly advantaged in some measures of cardiorespiratory stability.

Charpak 1994Non-randomized trial

Chiu 2009The study compared early KMC (N=52) and standard care (N=48) in late preterm infants (32 to <37 weeks' gestation). The study included infants with birthweight ≥2500 g. No data for subgroup of infants <2500 g at birth. KMC infants had lower infant teaching scores at six months than controls, a difference that disappeared thereafter. Feeding scores at 6 and 12 months follow up were similar for KMC infants and controls.

Christensson 1998The study compared SSC and incubator care for rewarming in 80 low-risk hypothermic infants (clinically stable with admission weight of ≥1500 g).

Chwo 2002The study compared SSC (N=17) and standard contact (N=17) in infants born at 34-36 weeks' gestation. 20 of 34 included infants (59%) had a birthweight >2500 g. No data for the remaining 14 LBW infants.

Dala Sierra 1994Non-randomized trial

Darmstadt 2006The study evaluated acceptance of KMC within a trial of impact of a package of essential newborn care.

de Almeida 2010Non-randomized trial

de Macedo 2007Non-randomized trial

Feldman 2002Non-randomized trial

Hake Brooks 2008The study compared KMC (N=36) and standard care (N=30) in preterm infants. The study included infants with birthweight of 1300-3000 g. 39% of included infants had a gestational age of 36 weeks. No data for subgroup of infants <2500 g at birth. KMC was associated with a significant longer breastfeeding duration and a higher frequency of exclusive breastfeeding at discharge, and at 1.5, 3, and 6 months.

Huang 2006The study compared early KMC (N=39) and use of radiant warmers (N=39) in term infants with hypothermia problems. Mean (SD) birthweight was 3072 (393) and 2808 (428) g for KMC and control infants, respectively. After 4 hours, more infants in the KMC group had reached normal body temperature.

Ibe 2004Non-randomized trial

Kambarami 1998Quasi-random allocation to treatment (alternation). 74 (37 per group) infants were subjected to KMC or incubator care. Infants in the KMC group had higher mean daily weight gain, shorter stay in hospital, and better survival rates.

Kumar 2008Cluster randomized controlled trial in which SSC was part of a preventive package of interventions for essential newborn care.

Lai 2006The study compared music during KMC (N=15) and standard care (N=15) in preterm infants. The study included infants with birthweight of 1505-3285 g. No data for subgroup of infants <2500 g at birth. In addition, the study did not report results for clinical outcomes.

Lamy Filho 2008Non-randomized trial.

Legault 1993Participant allocation was by a crossover recruitment design. Study did not report results for clinical outcomes.

Legault 1995Non-randomized trial.

Lincetto 2000Non-randomized trial.

Ludington-Hoe 1991Randomized controlled trial that compared KMC and standard care in cardiorespiratory, thermal and state effects in preterm infants. No data on neonatal morbidity and mortality.

Ludington-Hoe 2000Randomized controlled trial that compared KMC (N=16) and standard care (N=13) in maintenance of body warmth in preterm infants. No data on neonatal morbidity and mortality.

Ludington-Hoe 2004Randomized controlled trial that compared KMC (N=11) and standard care (N=13) for assessment of cardiorespiratory and thermal responses in preterm infants. No data on neonatal morbidity and mortality.

Ludington-Hoe 2006Randomized controlled trial that compared KMC (N=14) and standard care (N=14) for assessment of neonatal sleep organization in preterm infants. No data on neonatal morbidity and mortality.

Miles 2006The study was a pragmatic, controlled trial in which participant allocation was by a crossover, cluster recruitment design between two tertiary referral NICUs. Each hospital remained in KMC or control group for 4 months and then crossed over following a wash-out phase, during which no recruitment was undertaken. No significant difference was found in any infant or maternal measure at any time point.

Miltersteiner 2005Quasi-random allocation to treatment (even or odd number). Length of hospital stay was 8±1 days for the KMC group and 10±1.9 days for the control group (P=0.004).

Ohgi 2002Non-randomized trial.

Sloan 2008Randomized controlled cluster trial in which 4165 infants were assigned to community-based KMC or control. 40% overall and 65% of newborns who died were not weighed at birth, and missing birthweight was differential for study group. 68.6% of weighed infants had a birthweight ≥2500 g. There was no difference in overall neonatal mortality rate or infant mortality rate.

Tallandini 2006Non-randomized trial.

 
Characteristics of studies awaiting assessment [ordered by study ID]
Udani 2008

MethodsRandomized controlled trial performed in Mumbai, India between June 2001 and December 2001.

ParticipantsOne hundred LBW infants <1800 g.

InterventionsKMC using a kangaroo bag which was tailored to hold the baby doubly secured in between the mother's breast compared with conventional method of care.

OutcomesSerious illness, sepsis, hypothermia.

NotesAvailable in abstract form. The study was presented at the VII International Workshop on Kangaroo Mother Care. Uppsala, Sweden. October 6-7, 2008. Additional information on study methods and outcomes was requested to authors by e-mail.

 
Comparison 1. Kangaroo mother care versus conventional neonatal care

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

 1 Mortality at discharge or 40-41 weeks' postmenstrual age7Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    1.1 All studies
71614Risk Ratio (M-H, Fixed, 95% CI)0.60 [0.39, 0.93]

    1.2 Intermittent KMC
4497Risk Ratio (M-H, Fixed, 95% CI)0.60 [0.20, 1.85]

    1.3 Continuous KMC
31117Risk Ratio (M-H, Fixed, 95% CI)0.60 [0.38, 0.96]

    1.4 Infant age ≤10 days at initiation of KMC
51426Risk Ratio (M-H, Fixed, 95% CI)0.57 [0.36, 0.89]

    1.5 Infant age >10 days at initiation of KMC
2188Risk Ratio (M-H, Fixed, 95% CI)1.32 [0.22, 7.73]

    1.6 Low/middle income countries
61554Risk Ratio (M-H, Fixed, 95% CI)0.58 [0.37, 0.90]

    1.7 High income countries
160Risk Ratio (M-H, Fixed, 95% CI)1.64 [0.16, 17.09]

    1.8 infant entered into trial before stabilization
1123Risk Ratio (M-H, Fixed, 95% CI)0.57 [0.33, 1.00]

    1.9 infant entered into trial after stabilization
61491Risk Ratio (M-H, Fixed, 95% CI)0.63 [0.32, 1.24]

 2 Mortality at 6 months of age or 6 months follow up2354Risk Ratio (M-H, Fixed, 95% CI)0.99 [0.48, 2.02]

    2.1 Intermittent
171Risk Ratio (M-H, Fixed, 95% CI)1.03 [0.15, 6.90]

    2.2 Continuous
1283Risk Ratio (M-H, Fixed, 95% CI)0.98 [0.46, 2.12]

 3 Mortality at 12 months' corrected age1693Risk Ratio (M-H, Fixed, 95% CI)0.57 [0.27, 1.17]

   3.1 Intermittent
00Risk Ratio (M-H, Fixed, 95% CI)Not estimable

    3.2 Continuous
1693Risk Ratio (M-H, Fixed, 95% CI)0.57 [0.27, 1.17]

 4 Mortality at latest follow up9Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    4.1 All studies
91952Risk Ratio (M-H, Fixed, 95% CI)0.68 [0.48, 0.96]

    4.2 Intermittent KMC
5568Risk Ratio (M-H, Fixed, 95% CI)0.69 [0.26, 1.79]

    4.3 Continuous KMC
41384Risk Ratio (M-H, Fixed, 95% CI)0.67 [0.46, 0.98]

    4.4 Infant age ≤10 days at initiation of KMC
51410Risk Ratio (M-H, Fixed, 95% CI)0.57 [0.37, 0.86]

    4.5 Infant age >10 days at initiation of KMC
4542Risk Ratio (M-H, Fixed, 95% CI)1.03 [0.53, 2.00]

    4.6 Low/middle income countries
71821Risk Ratio (M-H, Fixed, 95% CI)0.65 [0.45, 0.93]

    4.7 High income countries
2131Risk Ratio (M-H, Fixed, 95% CI)1.25 [0.29, 5.42]

    4.8 infant entered into trial before stabilization
1123Risk Ratio (M-H, Fixed, 95% CI)0.57 [0.33, 1.00]

    4.9 infant entered into trial after stabilization
81829Risk Ratio (M-H, Fixed, 95% CI)0.73 [0.47, 1.14]

 5 Severe infection/sepsis at latest follow up - stabilized infants61250Risk Ratio (M-H, Fixed, 95% CI)0.57 [0.40, 0.80]

    5.1 Intermittent
5587Risk Ratio (M-H, Fixed, 95% CI)0.46 [0.28, 0.76]

    5.2 Continuous
1663Risk Ratio (M-H, Fixed, 95% CI)0.69 [0.43, 1.12]

 6 Severe illness at 6 months follow up - stabilized infants1283Risk Ratio (M-H, Fixed, 95% CI)0.30 [0.14, 0.67]

   6.1 intermittent
00Risk Ratio (M-H, Fixed, 95% CI)Not estimable

    6.2 Continuous
1283Risk Ratio (M-H, Fixed, 95% CI)0.30 [0.14, 0.67]

 7 Nosocomial infection/sepsis at discharge or 40-41 weeks' postmenstrual age - stabilized infants2777Risk Ratio (M-H, Fixed, 95% CI)0.42 [0.24, 0.73]

    7.1 Intermittent
1114Risk Ratio (M-H, Fixed, 95% CI)0.30 [0.10, 0.86]

    7.2 Continuous
1663Risk Ratio (M-H, Fixed, 95% CI)0.49 [0.25, 0.93]

 8 Mild/moderate infection or illness at latest follow up - stabilized infants41266Risk Ratio (M-H, Random, 95% CI)1.28 [0.87, 1.88]

    8.1 Intermittent
2320Risk Ratio (M-H, Random, 95% CI)1.52 [0.43, 5.38]

    8.2 Continuous
2946Risk Ratio (M-H, Random, 95% CI)1.42 [0.53, 3.79]

 9 Lower respiratory tract disease at 6 months follow up - stabilized infants1283Risk Ratio (M-H, Fixed, 95% CI)0.37 [0.15, 0.89]

   9.1 Intermittent
00Risk Ratio (M-H, Fixed, 95% CI)Not estimable

    9.2 Continuous
1283Risk Ratio (M-H, Fixed, 95% CI)0.37 [0.15, 0.89]

 10 Diarrhea at 6 months follow up - stabilized infants1283Risk Ratio (M-H, Fixed, 95% CI)0.65 [0.35, 1.20]

   10.1 Intermittent
00Risk Ratio (M-H, Fixed, 95% CI)Not estimable

    10.2 Continuous
1283Risk Ratio (M-H, Fixed, 95% CI)0.65 [0.35, 1.20]

 11 Hypothermia at discharge or 40-41 weeks' postmenstrual age - stabilized infants4469Risk Ratio (M-H, Random, 95% CI)0.23 [0.10, 0.55]

    11.1 Intermittent
4469Risk Ratio (M-H, Random, 95% CI)0.23 [0.10, 0.55]

   11.2 Continuous
00Risk Ratio (M-H, Random, 95% CI)Not estimable

 12 Readmission to hospital at latest follow up - stabilized infants2946Risk Ratio (M-H, Fixed, 95% CI)0.60 [0.34, 1.06]

   12.1 Intermittent
00Risk Ratio (M-H, Fixed, 95% CI)Not estimable

    12.2 Continuous
2946Risk Ratio (M-H, Fixed, 95% CI)0.60 [0.34, 1.06]

 13 Weight gain at latest follow up (g/day) - stabilized infants9936Mean Difference (IV, Random, 95% CI)3.86 [1.87, 5.84]

    13.1 Intermittent
8651Mean Difference (IV, Random, 95% CI)3.87 [1.67, 6.08]

    13.2 Continuous
1285Mean Difference (IV, Random, 95% CI)3.60 [0.78, 6.42]

 14 Weight at discharge or 40-41 weeks' postmenstrual age (g) - stabilized infants41097Mean Difference (IV, Fixed, 95% CI)21.65 [-15.98, 59.27]

    14.1 Intermittent
2149Mean Difference (IV, Fixed, 95% CI)63.54 [-2.58, 129.67]

    14.2 Continuous
2948Mean Difference (IV, Fixed, 95% CI)1.59 [-44.16, 47.34]

 15 Weight at 6 months' corrected age (g) - stabilized infants1591Mean Difference (IV, Fixed, 95% CI)78.19 [-52.26, 208.64]

   15.1 Intermittent
00Mean Difference (IV, Fixed, 95% CI)Not estimable

    15.2 Continuous
1591Mean Difference (IV, Fixed, 95% CI)78.19 [-52.26, 208.64]

 16 Weight at 12 months' corrected age (g) - stabilized infants1596Mean Difference (IV, Fixed, 95% CI)31.46 [-135.08, 198.00]

   16.1 Intermittent
00Mean Difference (IV, Fixed, 95% CI)Not estimable

    16.2 Continuous
1596Mean Difference (IV, Fixed, 95% CI)31.46 [-135.08, 198.00]

 17 Length gain at latest follow up (cm/week) - stabilized infants2251Mean Difference (IV, Fixed, 95% CI)0.29 [0.27, 0.31]

    17.1 Intermittent
2251Mean Difference (IV, Fixed, 95% CI)0.29 [0.27, 0.31]

   17.2 Continuous
00Mean Difference (IV, Fixed, 95% CI)Not estimable

 18 Length at discharge or 40-41 weeks' postmenstrual age (cm) - stabilized infants2720Mean Difference (IV, Fixed, 95% CI)0.06 [-0.28, 0.39]

    18.1 Intermittent
157Mean Difference (IV, Fixed, 95% CI)0.40 [-0.48, 1.28]

    18.2 Continuous
1663Mean Difference (IV, Fixed, 95% CI)Not estimable

 19 Length at 6 months' corrected age (cm) - stabilized infants1590Mean Difference (IV, Fixed, 95% CI)0.23 [-0.18, 0.64]

   19.1 Intermittent
00Mean Difference (IV, Fixed, 95% CI)Not estimable

    19.2 Continuous
1590Mean Difference (IV, Fixed, 95% CI)0.23 [-0.18, 0.64]

 20 Length at 12 months' corrected age (cm) - stabilized infants1586Mean Difference (IV, Fixed, 95% CI)0.31 [-0.17, 0.79]

   20.1 Intermittent
00Mean Difference (IV, Fixed, 95% CI)Not estimable

    20.2 Continuous
1586Mean Difference (IV, Fixed, 95% CI)0.31 [-0.17, 0.79]

 21 Head circumference gain at latest follow up (cm/week) - stabilized infants3369Mean Difference (IV, Random, 95% CI)0.18 [0.09, 0.27]

    21.1 Intermittent
3369Mean Difference (IV, Random, 95% CI)0.18 [0.09, 0.27]

   21.2 Continuous
00Mean Difference (IV, Random, 95% CI)Not estimable

 22 Head circumference at discharge or 40-41 weeks' postmenstrual age (cm) - stabilized infants2720Mean Difference (IV, Random, 95% CI)0.39 [-0.28, 1.07]

    22.1 Intermittent
157Mean Difference (IV, Random, 95% CI)0.80 [0.20, 1.40]

    22.2 Continuous
1663Mean Difference (IV, Random, 95% CI)0.10 [-0.14, 0.34]

 23 Head circumference at 6 months' corrected age (cm) - stabilized infants1592Mean Difference (IV, Fixed, 95% CI)0.34 [0.11, 0.57]

   23.1 Intermittent
00Mean Difference (IV, Fixed, 95% CI)Not estimable

    23.2 Continuous
1592Mean Difference (IV, Fixed, 95% CI)0.34 [0.11, 0.57]

 24 Head circumference at 12 months' corrected age (cm) - stabilized infants1597Mean Difference (IV, Fixed, 95% CI)0.39 [-0.00, 0.78]

   24.1 Intermittent
00Mean Difference (IV, Fixed, 95% CI)Not estimable

    24.2 Continuous
1597Mean Difference (IV, Fixed, 95% CI)0.39 [-0.00, 0.78]

 25 Psychomotor development (Griffith quotients) at 12 months' corrected age1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    25.1 Locomotion
1579Mean Difference (IV, Fixed, 95% CI)2.25 [-0.45, 4.95]

    25.2 Personal, social
1579Mean Difference (IV, Fixed, 95% CI)0.97 [-1.27, 3.21]

    25.3 Hand-eye coordination
1579Mean Difference (IV, Fixed, 95% CI)0.57 [-1.25, 2.39]

    25.4 Audition, language
1579Mean Difference (IV, Fixed, 95% CI)1.29 [-0.98, 3.56]

    25.5 Execution
1579Mean Difference (IV, Fixed, 95% CI)0.30 [-1.50, 2.10]

    25.6 All criteria
1579Mean Difference (IV, Fixed, 95% CI)1.05 [-0.75, 2.85]

 26 Cerebral palsy at 12 months' corrected age1588Risk Ratio (M-H, Fixed, 95% CI)0.65 [0.21, 2.02]

 27 Deafness at 12 months' corrected age1588Risk Ratio (M-H, Fixed, 95% CI)0.30 [0.03, 2.90]

 28 Visual impairment at 12 months' corrected age1588Risk Ratio (M-H, Fixed, 95% CI)0.91 [0.53, 1.56]

 29 Exclusive breast feeding at discharge or 40-41 weeks' postmenstrual age - stabilized infants41197Risk Ratio (M-H, Random, 95% CI)1.21 [1.08, 1.36]

    29.1 Intermittent
2255Risk Ratio (M-H, Random, 95% CI)1.29 [1.15, 1.44]

    29.2 Continuous
2942Risk Ratio (M-H, Random, 95% CI)1.14 [0.92, 1.42]

 30 Exclusive breast feeding at 1-3 months follow up - stabilized infants5600Risk Ratio (M-H, Random, 95% CI)1.20 [1.01, 1.43]

    30.1 Intermittent
3221Risk Ratio (M-H, Random, 95% CI)1.36 [1.12, 1.65]

    30.2 Continuous
2379Risk Ratio (M-H, Random, 95% CI)1.03 [0.96, 1.10]

 31 Exclusive breast feeding at 6-12 months follow up - stabilized infants3810Risk Ratio (M-H, Fixed, 95% CI)1.29 [0.95, 1.76]

    31.1 Intermittent
175Risk Ratio (M-H, Fixed, 95% CI)1.52 [1.10, 2.10]

    31.2 Continuous
2735Risk Ratio (M-H, Fixed, 95% CI)1.10 [0.66, 1.86]

 32 Any breast feeding at discharge or 40-41 weeks' postmenstrual age - stabilized infants81440Risk Ratio (M-H, Random, 95% CI)1.25 [1.06, 1.47]

    32.1 Intermittent
6498Risk Ratio (M-H, Random, 95% CI)1.31 [1.11, 1.55]

    32.2 Continuous
2942Risk Ratio (M-H, Random, 95% CI)1.14 [0.93, 1.40]

 33 Any breast feeding at 1-2 months follow up - stabilized infants6538Risk Ratio (M-H, Random, 95% CI)1.33 [1.00, 1.78]

    33.1 Intermittent
4159Risk Ratio (M-H, Random, 95% CI)1.89 [1.30, 2.75]

    33.2 Continuous
2379Risk Ratio (M-H, Random, 95% CI)1.03 [0.96, 1.10]

 34 Any breast feeding at 3 months follow up - stabilized infants5924Risk Ratio (M-H, Fixed, 95% CI)1.14 [1.06, 1.23]

    34.1 Intermittent
4261Risk Ratio (M-H, Fixed, 95% CI)1.35 [1.15, 1.59]

    34.2 Continuous
1663Risk Ratio (M-H, Fixed, 95% CI)1.08 [1.00, 1.17]

 35 Any breast feeding at 6 months follow up - stabilized infants5952Risk Ratio (M-H, Fixed, 95% CI)1.12 [0.98, 1.29]

    35.1 Intermittent
3143Risk Ratio (M-H, Fixed, 95% CI)1.50 [1.08, 2.08]

    35.2 Continuous
2809Risk Ratio (M-H, Fixed, 95% CI)1.07 [0.92, 1.24]

 36 Any breast feeding at 12 months follow up - stabilized infants1589Risk Ratio (M-H, Fixed, 95% CI)0.89 [0.65, 1.21]

   36.1 Intermittent
00Risk Ratio (M-H, Fixed, 95% CI)Not estimable

    36.2 Continuous
1589Risk Ratio (M-H, Fixed, 95% CI)0.89 [0.65, 1.21]

 37 Onset of breast feeding (days) - stabilized infants2295Mean Difference (IV, Random, 95% CI)0.03 [-1.64, 1.70]

    37.1 Intermittent
2295Mean Difference (IV, Random, 95% CI)0.03 [-1.64, 1.70]

   37.2 Continuous
00Mean Difference (IV, Random, 95% CI)Not estimable

 38 Length of hospital stay (days) - stabilized infants9795Mean Difference (IV, Random, 95% CI)-2.41 [-4.11, -0.71]

    38.1 Intermittent
9795Mean Difference (IV, Random, 95% CI)-2.41 [-4.11, -0.71]

   38.2 Continuous
00Mean Difference (IV, Random, 95% CI)Not estimable

 39 Parental and familiar satisfaction (continuous KMC)1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    39.1 Mother satisfied with method
1269Risk Ratio (M-H, Fixed, 95% CI)1.17 [1.05, 1.30]

    39.2 Father satisfied with method
1269Risk Ratio (M-H, Fixed, 95% CI)1.02 [0.91, 1.14]

    39.3 Family satisfied with method
1269Risk Ratio (M-H, Fixed, 95% CI)0.97 [0.83, 1.13]

 40 Mother-infant attachment: mother's feelings and perceptions according to interval between birth and start of intervention, and infant admission to NICU1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    40.1 Sense of competence - interval of 1-2 days
1170Mean Difference (IV, Fixed, 95% CI)0.41 [0.14, 0.68]

    40.2 Sense of competence - interval of 3-14 days
1177Mean Difference (IV, Fixed, 95% CI)0.25 [-0.08, 0.58]

    40.3 Sense of competence - interval >14 days
1141Mean Difference (IV, Fixed, 95% CI)0.21 [-0.17, 0.59]

    40.4 Sense of competence - infant admitted to NICU
182Mean Difference (IV, Fixed, 95% CI)0.54 [0.07, 1.01]

    40.5 Sense of competence - infant not admitted to NICU
1406Mean Difference (IV, Fixed, 95% CI)0.24 [0.05, 0.43]

    40.6 Worry and stress - interval of 1-2 days
1170Mean Difference (IV, Fixed, 95% CI)0.31 [0.04, 0.58]

    40.7 Worry and stress - interval of 3-14 days
1177Mean Difference (IV, Fixed, 95% CI)0.09 [-0.20, 0.38]

    40.8 Worry and stress - interval >14 days
1141Mean Difference (IV, Fixed, 95% CI)-0.29 [-0.70, 0.12]

    40.9 Worry and stress - infant admitted to NICU
182Mean Difference (IV, Fixed, 95% CI)-0.1 [-0.60, 0.40]

    40.10 Worry and stress - infant not admitted to NICU
1406Mean Difference (IV, Fixed, 95% CI)0.12 [-0.06, 0.30]

    40.11 Social support - interval of 1-2 days
1170Mean Difference (IV, Fixed, 95% CI)-0.06 [-0.35, 0.23]

    40.12 Social support - interval of 3-14 days
1177Mean Difference (IV, Fixed, 95% CI)-0.06 [-0.34, 0.22]

    40.13 Social support - interval >14 days
1141Mean Difference (IV, Fixed, 95% CI)-0.47 [-0.84, -0.10]

    40.14 Social support - infant admitted to NICU
182Mean Difference (IV, Fixed, 95% CI)-0.05 [-0.52, 0.42]

    40.15 Social support - infant not admitted to NICU
1406Mean Difference (IV, Fixed, 95% CI)-0.2 [-0.39, -0.01]

 41 Mother-infant attachment: mother's responses to the infant according to interval between birth and start of intervention, and infant admission to NICU1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    41.1 Mother's sensitivity - interval of 1-2 days
1170Mean Difference (IV, Fixed, 95% CI)0.02 [-0.02, 0.06]

    41.2 Mother's sensitivity - interval of 3-14 days
1177Mean Difference (IV, Fixed, 95% CI)-0.01 [-0.05, 0.03]

    41.3 Mother's sensitivity - interval >14 days
1141Mean Difference (IV, Fixed, 95% CI)0.06 [0.01, 0.11]

    41.4 Mother's sensitivity - infant admitted to NICU
182Mean Difference (IV, Fixed, 95% CI)0.02 [-0.04, 0.08]

    41.5 Mother's sensitivity - infant not admitted to NICU
1406Mean Difference (IV, Fixed, 95% CI)0.02 [-0.00, 0.04]

    41.6 Mother's response to child's distress - interval of 1-2 days
1170Mean Difference (IV, Fixed, 95% CI)-0.03 [-0.08, 0.02]

    41.7 Mother's response to child's distress - interval of 3-14 days
1177Mean Difference (IV, Fixed, 95% CI)0.01 [-0.03, 0.05]

    41.8 Mother's response to child's distress - interval >14 days
1141Mean Difference (IV, Fixed, 95% CI)0.01 [-0.04, 0.06]

    41.9 Mother's response to child's distress - infant admitted to NICU
182Mean Difference (IV, Fixed, 95% CI)0.05 [-0.01, 0.11]

    41.10 Mother's response to child's distress - infant not admitted to NICU
1406Mean Difference (IV, Fixed, 95% CI)-0.02 [-0.05, 0.01]

    41.11 Mother's response to child's socioemotional growth fostering - interval of 1-2 days
1170Mean Difference (IV, Fixed, 95% CI)0.01 [-0.04, 0.06]

    41.12 Mother's response to child's socioemotional growth fostering - interval of 3-14 days
1177Mean Difference (IV, Fixed, 95% CI)-0.02 [-0.06, 0.02]

    41.13 Mother's response to child's socioemotional growth fostering - interval >14 days
1141Mean Difference (IV, Fixed, 95% CI)0.05 [-0.00, 0.10]

    41.14 Mother's response to child's socioemotional growth fostering - infant admitted to NICU
182Mean Difference (IV, Fixed, 95% CI)-0.05 [-0.12, 0.02]

    41.15 Mother's response to child's socioemotional growth fostering - infant not admitted to NICUNICU
1406Mean Difference (IV, Fixed, 95% CI)0.02 [-0.01, 0.05]

    41.16 Mother's response to child's cognitive growth fostering - interval of 1-2 days
1170Mean Difference (IV, Fixed, 95% CI)0.02 [-0.04, 0.08]

    41.17 Mother's response to child's cognitive growth fostering - interval of 3-14 days
1177Mean Difference (IV, Fixed, 95% CI)-0.04 [-0.10, 0.02]

    41.18 Mother's response to child's cognitive growth fostering - interval >14 days
1141Mean Difference (IV, Fixed, 95% CI)0.07 [0.00, 0.14]

    41.19 Mother's response to child's cognitive growth fostering - infant admitted to NICU
182Mean Difference (IV, Fixed, 95% CI)-0.07 [-0.17, 0.03]

    41.20 Mother's response to child's cognitive growth fostering - infant not admitted to NICU
1406Mean Difference (IV, Fixed, 95% CI)0.03 [-0.01, 0.07]

 42 Mother-infant attachment: infant's responses to the mother according to interval between birth and start of intervention, and infant admission to NICU1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    42.1 Clarity of cues - interval of 1-2 days
1170Mean Difference (IV, Fixed, 95% CI)0.01 [-0.04, 0.06]

    42.2 Clarity of cues - interval of 3-14 days
1177Mean Difference (IV, Fixed, 95% CI)0.02 [-0.03, 0.07]

    42.3 Clarity of cues - interval >14 days
1141Mean Difference (IV, Fixed, 95% CI)Not estimable

    42.4 Clarity of cues - infant admitted to NICU
182Mean Difference (IV, Fixed, 95% CI)-0.01 [-0.07, 0.05]

    42.5 Clarity of cues - infant not admitted to NICU
1406Mean Difference (IV, Fixed, 95% CI)0.02 [-0.01, 0.05]

    42.6 Responsiveness - interval of 1-2 days
1170Mean Difference (IV, Fixed, 95% CI)-0.02 [-0.06, 0.02]

    42.7 Responsiveness - interval of 3-14 days
1177Mean Difference (IV, Fixed, 95% CI)0.02 [-0.02, 0.06]

    42.8 Responsiveness - interval >14 days
1141Mean Difference (IV, Fixed, 95% CI)0.05 [0.01, 0.09]

    42.9 Responsiveness - infant admitted to NICU
182Mean Difference (IV, Fixed, 95% CI)-0.01 [-0.07, 0.05]

    42.10 Responsiveness - infant not admitted to NICU
1406Mean Difference (IV, Fixed, 95% CI)0.02 [-0.01, 0.05]

 43 Mother-infant attachment at 3 months follow-up1100Mean Difference (IV, Fixed, 95% CI)6.24 [5.57, 6.91]

    43.1 Total attachment score at 3 months follow-up
1100Mean Difference (IV, Fixed, 95% CI)6.24 [5.57, 6.91]

 44 Mother-infant attachment: stress in NICU1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    44.1 Nursery environment score
130Mean Difference (IV, Fixed, 95% CI)0.10 [-0.51, 0.71]

    44.2 Infant appearance score
130Mean Difference (IV, Fixed, 95% CI)Not estimable

    44.3 Relationship with the infant score
130Mean Difference (IV, Fixed, 95% CI)1.00 [0.35, 1.65]

    44.4 Staff behavior and communication score
130Mean Difference (IV, Fixed, 95% CI)0.10 [-0.95, 1.15]

 45 Mother-infant attachment: parenting skills130Mean Difference (IV, Fixed, 95% CI)-0.40 [-0.89, 0.09]

    45.1 Total score at discharge
130Mean Difference (IV, Fixed, 95% CI)-0.40 [-0.89, 0.09]

 46 Mother-infant interaction at 6 months follow-up1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    46.1 Symmetrical coregulation
145Mean Difference (IV, Fixed, 95% CI)16.38 [13.61, 19.15]

    46.2 Asymmetrical coregulation
145Mean Difference (IV, Fixed, 95% CI)-18.31 [-21.42, -15.20]

    46.3 Unilateral regulation
145Mean Difference (IV, Fixed, 95% CI)2.12 [-1.24, 5.48]

 47 Social and home environment1338Mean Difference (IV, Fixed, 95% CI)0.79 [0.74, 0.84]

    47.1 HOME environment total score at 12 months' corrected age
1338Mean Difference (IV, Fixed, 95% CI)0.79 [0.74, 0.84]

 
Comparison 2. Early versus late kangaroo mother care in relatively stable LBW infants

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

 1 Mortality at 4 weeks of age173Risk Ratio (M-H, Fixed, 95% CI)1.95 [0.18, 20.53]

 2 Morbidity at 4 weeks of age173Risk Ratio (M-H, Fixed, 95% CI)0.49 [0.18, 1.28]

 3 Severe infection at 4 weeks of age173Risk Ratio (M-H, Fixed, 95% CI)0.42 [0.12, 1.49]

 4 Re-admission to hospital at 4 weeks of age173Risk Ratio (M-H, Fixed, 95% CI)1.95 [0.18, 20.53]

 5 Hypothermia173Risk Ratio (M-H, Fixed, 95% CI)0.58 [0.15, 2.27]

 6 Weight gain (grams)1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    6.1 At 24 hours postbirth
173Mean Difference (IV, Fixed, 95% CI)39.16 [11.11, 67.21]

    6.2 At 48 hours postbirth
173Mean Difference (IV, Fixed, 95% CI)43.3 [5.49, 81.11]

    6.3 At 2 weeks of age
173Mean Difference (IV, Fixed, 95% CI)12.14 [-83.18, 107.46]

    6.4 At 4 weeks of age
173Mean Difference (IV, Fixed, 95% CI)58.85 [-116.93, 234.63]

 7 Exclusive breast feeding1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    7.1 At 24 hours of age
173Risk Ratio (M-H, Fixed, 95% CI)1.02 [0.67, 1.57]

    7.2 At 2 weeks of age
171Risk Ratio (M-H, Fixed, 95% CI)1.00 [0.89, 1.12]

    7.3 At 4 weeks of age
167Risk Ratio (M-H, Fixed, 95% CI)0.94 [0.85, 1.04]

 8 Length of hospital stay (days)173Mean Difference (IV, Fixed, 95% CI)-0.90 [-1.24, -0.56]