Guidelines for the nursing management of gestational diabetes mellitus: An integrative literature review

Abstract Aims and objectives An integrative literature review searched for, selected, appraised, extracted and synthesized data from existing available guidelines on the nursing management of gestational diabetes mellitus as no such analysis has been found. Background Early screening, diagnosis and management of gestational diabetes mellitus are important to prevent or reduce complications during and postpregnancy for both mother and child. A variety of guidelines exists, which assist nurses and midwives in the screening, diagnosis and management of gestational diabetes mellitus. Design An integrative literature review. Methods The review was conducted in June 2018 following an extensive search of available guidelines according to an adaptation of the stages reported by Whittemore and Knafl (2005, Journal of Advanced Nursing, 52, 546). Thus, a five‐step process was used, namely formulation of the review question, literature search, critical appraisal of guidelines identified, data extraction and data analysis. All relevant guidelines were subsequently appraised for rigour and quality by two independent reviewers using the AGREE II tool. Content analysis was used analysing the extracted data. Results Following extraction and analysis of data, two major themes were identified from eighteen (N = 18) guidelines. These were the need for early screening and diagnosis of gestational diabetes mellitus and for nursing management of gestational diabetes mellitus (during pregnancy, intra‐ and postpartum management). Various guidelines on the nursing management of gestational diabetes mellitus were found; however, guidelines were not always comprehensive, sometimes differed in their recommended practices and did not consider a variety of contextual barriers to the implementation of the recommendations. Conclusion Critically, scrutiny of the guidelines is required, both in terms of the best evidence used in their development and in terms of the feasibility of implementation for its context. Relevance to clinical practice This study provides a summary of best practices regarding the diagnosis, screening and nursing management of gestational diabetes mellitus that provide guidance for nurse–midwives on maternal and postpartum follow‐up care for women at risk or diagnosed with gestational diabetes mellitus.


| INTRODUC TI ON
The prevalence of gestational diabetes mellitus (GDM) varies per country but is estimated to be approximately 15% among pregnant women globally (Zhu & Zhang, 2016). However, the global prevalence is expected to increase due to increasing numbers of overweight and obese women of reproductive age (Guariguata, Linnenkamp, Beagley, Whithing, & Cho, 2014;Kampmann et al., 2015). During 2003During -2014 prevalence of pregnant women with overweight and obesity increased in high middle-income countries mainly due to increased caloric supply and urbanization and in upper middle-and lower middle-income countries as a result of the decreased employment of women in agricultural activities (Chen, Xu, & Yan, 2018). GDM is defined as any degree of glucose intolerance with onset or first recognition during pregnancy (American Diabetes Association [ADA], 2010). GDM characterizes the most common metabolic complication of pregnancy and is related to maternal complications such as hypertension, pre-eclampsia, caesarean section, infection and polyhydramnios. It is also related to foetal morbidity in terms of macrosomia, birth trauma, hypoglycaemia, hypocalcaemia, hypomagnesemia, hyperbilirubinemia, respiratory distress syndrome and polycythemia (Mitanchez, Yzydorczyk, & Simeoni, 2015;Rafiq, Hussain, Jan, & Najar, 2015).
Additionally, women diagnosed with GDM are considerably more at risk for impaired glucose tolerance and are up to six times more likely to develop type 2 diabetes 5-10 years postpregnancy compared with women with normal glucose levels in pregnancy (Work Loss Data Institute, 2016). Furthermore, children from women with GDM have a higher likelihood of developing obesity and of having impaired glucose tolerance as well as diabetes, either in childhood or in early adulthood (World Health Organization [WHO], 2016).
Some risk factors that are identified for developing GDM include age (the risk for GDM increases with age), being overweight or obese, extreme weight gain during pregnancy and a family history of diabetes. Additional risk factors related to an increased frequency of GDM include GDM during an earlier pregnancy, a history of stillbirth or giving birth to an infant with congenital abnormalities and detection of glucose in the urine as well as ethnic background (Anna, van der Ploeg, Cheung, Huxley, & Bauman, 2008;Evensen, 2012;Kampmann et al., 2015;Khan, Ali, & Khan, 2013).
Early screening and diagnosis of GDM is therefore important to prevent or reduce complications during and postpregnancy for both mother and child. Most countries use selective screening, based on the known risk factors. Although selective screening could miss GDM cases, it could also assist nursing management by focussing health resources on women with the highest risk of complications, specifically in contexts where resources are scarce. Likewise, screening early in pregnancy for pre-existent diabetes by determining fasting glucose is justified, especially in the context of increased existence of diabetes mellitus type 2 in young women, which often remains undiagnosed (Kampmann et al., 2015).
Once women are diagnosed with GDM, management includes lifestyle modifications in terms of a diet high in dietary fibre (specifically fruit and cereal) and with a low glycaemic index, as well as routine monitoring of blood glucose levels during and postpregnancy.
Additionally, if needed, the GDM is treated by means of insulin, metformin and glyburide to ensure the long-term health of the pregnant woman and her baby (ADA, 2015;Poomalar, 2015).
A guideline, developed from rigorous evidence, would assist nurses and midwives in the screening, diagnosis and management of GDM. As they are often the first point of care for women, this is particularly important in contexts where medical care is scarce.
Although some guidelines on the management of GDM exist, they are often designed for medical practitioners. No study was found that summarized best practice guidelines regarding the nursing management of GDM. This study therefore searched for, selected, appraised, extracted and synthesized data from existing available guidelines to guide the development of a best practice guideline for the nursing management of GDM.

| ME THODS
An integrative literature review was conducted following a fivestep process adopted from Whittemore and Knafl (2005). The processes proceeded as follows: Step 1: Formulation of the review question; Step 2: Literature searching; Step 3: Critical appraisal of evidence; Step 4: Data extraction; and Step 5: Data analysis. The integrative literature review was conducted by the first author, under supervision of the second and third authors, both of whom are experienced in conducting integrative literature reviews. The study was part of a larger study that aimed to develop a best practice guideline for the nursing management of GDM during the ante-, intra-and postnatal periods.

| Formulation of the review question
The review question (Step 1) was formulated according to the PICO format. The elements of the question were as follows: mellitus that provide guidance for nurse-midwives on maternal and postpartum follow-up care for women at risk or diagnosed with gestational diabetes mellitus.

K E Y W O R D S
best practices, diagnosis, gestational diabetes mellitus, guidelines, midwife, nurse, nursing management, screening P -Population = Women; I -Issue = nursing management of GDM (including screening, diagnosis and management); C -Context = nursing and health institutions; O -Outcome = to inform best practices on the nursing management of GDM. The review question was therefore formulated as follows: What existing evidence is available to inform best practices on the nursing management of women diagnosed with GDM?

| Literature searching process
The literature searching process (Step 2) was conducted with the assistance of an experienced librarian in selecting the databases and keywords. Inclusion and exclusion criteria were established to guide the search and selection process.

| Key words
With the assistance of an experienced librarian, the combination of key words "guideline*" and "evidence-based practice" and "gestational diabetes mellitus" AND "nurs* manage* OR nurs* intervention*" and "pregnan*, antenatal, intra-natal OR postnatal*" was used.
The combination of keywords used was adapted per database, if necessary, to obtain all relevant guidelines.

| Inclusion and exclusion criteria
Guidelines were included that focussed on the nursing management of GDM where any of the following aspects are addressed: early screening for GDM and its management, self-monitoring of blood glucose levels, lifestyle modifications and/or insulin administration.
Studies published in English were used as this is the language the authors are proficient in. Guidelines published between 2004Guidelines published between -2018 were included, and the most updated version of guidelines was included. Guidelines focussing on the management of type 1 or type 2 diabetes mellitus only were excluded as were guidelines that did not consider the practices of nurses or midwives in GDM management.

| Search and selection process
The search for appropriate guidelines was conducted in June 2018.
All guidelines that fitted the criteria for the study were retrieved and selected for inclusion. Guidelines that did not meet the required criteria were excluded. The inclusion and exclusion criteria were applied by both the first author and the fourth author (who served as an independent reviewer). Consensus regarding the inclusion and exclusion of relevant articles was reached between the authors. The search and selection process of the included guidelines is illustrated in Figure 1

| Critical appraisal
The AGREE II instrument was used to critically appraise the guidelines (Step 3). AGREE II consists of 23 appraisal items organized within six domains, followed by two global rating items for an overall assessment. Each domain captures a specific aspect of guideline quality. All AGREE II items were rated on a 7-point scale (1 -"Strongly disagree", when no relevant information was given, to 7 -"Strongly agree", when the quality of reporting was exceptional and the criterion was fully met) (Brouwers et al., 2010). The rating for each item was done depending on the completeness and quality of reporting.
The overall score allocated to each guideline appraised was expressed as a percentage of the maximum possible score of 161.
Guidelines with a score of 60 per cent were included as they were considered to have more rigour than guidelines with a lower score.
Similarly, they were considered to contribute more weight to the discussion and recommendations derived from the review. Consensus was reached between the two reviewers (the first and fourth author), as a result of which one of the nineteen guidelines was excluded owing to poor rigour. A total of 18 guidelines were included for data extraction (Figure 1).

| Data extraction process
After critical appraisal, data were extracted from eighteen guidelines ( Step 4). This process was completed by the first and fourth authors, working independently. Data extraction focused on material relating to early screening and diagnosis of GDM and the nursing management of GDM.

| Data analysis process
Thematic data analysis was used to systematically synthesize the extracted data of each guideline and develop themes (Step 5) (Burls, 2009). Consensus was achieved between the authors on the themes.

| Ethical statement
The study obtained ethics from the University's Faculty Postgraduate Studies Committee (ethics number: H14-HEA-NUR-32). The authors adhered to principles of honesty and transparency in reporting the data. Consent was not obtained, since this study had no participants.

| RE SULTS
Data extracted from the eighteen guidelines resulted in two main themes. They are, in outline, as follows: 1. Early screening and diagnosis of GDM; and 2. Nursing management of GDM (during pregnancy, intra-and postpartum management) ( that most guidelines mentioned the nursing management of GDM during pregnancy (N = 17), followed by early screening and diagnosis of GDM (N = 16) and postpartum nursing management of GDM (N = 14). Intrapartum nursing management of GDM was least mentioned by the guidelines (N = 7). Table 2 provides a summary of the main recommendations per guideline, which are further discussed below.  Queensland, 2015;SIGN, 2017;SEMDSA, 2017;WHO, 2013) recommend a fasting plasma glucose of 5.1-6.9 mM, 1-hr value of >10.0 mM and 2-hr value 8.5-11.0, according to NICE (2015), fasting values are <5.6 mM and 2 hr 7.8mM.

| Early screening and diagnosis of GDM
Specific aspects needing consideration during early screening and diagnosis are identified by various guidelines. For example, Blumer et al. (2013) recommend that the 75g OGTT be done after at least eight (8) hours night fast but not more than fourteen (14) hours. They further recommend that the usual intake of carbohy-

| Nursing management of GDM
Nursing management of GDM is a theme that is consistently featured in the guidelines that were included in the review. GDM management includes glycaemic control and monitoring and lifestyle modifications (diet and physical activity/exercise). Recommendations included those that should be used during pregnancy and intra-and postpartum.

| During pregnancy
Glycaemic control and monitoring during pregnancy must be done, for example, once a week and thereafter every 2-3 weeks until deliv- with the dietician and also to monitor her blood glucose levels as scheduled.
In terms of exercise, moderate exercise is recommended, such as a 30 min' (at least 10-min periods) (Queensland, 2015) walk after meals (Blumer et al., 2013;NICE, 2015) or 1 hr a day (Permanente, 2018). Education should also be given about armchair exercises

(American College of Obstetrics & Gynaecology [ACOG], 2018a).
To provide the best nursing management for GDM, a customized plan of care, especially for women at high risk, should be developed (NICE, 2015) that is individualized and culturally sensitive (International Diabetes Federation, 2009). This care plan could also include checks of blood pressure and dipstick urine protein every 1-2 weeks (resourced settings) or monthly (low-resource settings; FIGO, 2015;International Diabetes Federation, 2009;Queensland, 2015) as well as an ultrasound between 30-32 weeks of gestation to estimate foetal weight (Queensland, 2015) or every four weeks from 28-36 weeks of gestation (Ministry of Health Malaysia, 2017).

| Intrapartum
Although the woman should be given enough glucose during labour to help her to cope with the high level of energy demands for labour and for delivery so as to prevent the woman from having hypoglycaemia (Diabetes Canada, 2018;NICE, 2015;SEMDSA, 2017). NICE (2015) recommends that, if the capillary plasma glucose is above 7 mM, intravenous dextrose and insulin infusion must be given during labour and delivery, although the guideline does not specify how much.  (Blumer et al., 2013;Diabetes Australia/RACGP, 2016;NICE, 2015;Queensland, 2015). Blumer et al. (2013) is the only guideline that recommends, besides the 6-to 12-week screening, that blood glucose monitoring should also be done 24-72 hr after delivery. This is to rule out high blood glucose levels just after delivery.

| Postpartum
Most guidelines prefer a follow-up of screening varying between 1 year (NICE, 2015;Permanente, 2018;SEMDSA, 2017)  skilled lactation support is therefore recommended (Queensland, 2015;FIGO, 2015). Finally, extra attention is also required to detect early signs of genitourinary, uterine and surgical site infections (in the case of an episiotomy and caesarean delivery; FIGO, 2015).

| Comprehensiveness of the guidelines
Several guidelines from a variety of healthcare organizations, associations or health departments were found that include aspects relevant to the nursing management of GDM. Not all guidelines focus on all aspects (namely glycaemic control, monitoring and treatment and lifestyle moderations, including diet and physical activity/ exercise) and phases of the nursing management of GDM (during pregnancy, intrapartum as well as postpartum) as only 8 (N = 8) of the guidelines reviewed include all phases of the management of GDM (ACOG, 2018a;Diabetes Canada, 2018;NICE, 2015;Permanente, 2018;Queensland, 2015;SEMDSA, 2017;FIGO, 2015). There were guidelines which cover some of the phases or the nursing management of GDM in general. For example, the SIGN (2017)

| Quality of evidence
Not all guidelines reviewed included the level or grades of evidence used for each recommendation and various levels or grades were used. This is required to select a recommendation for implementation that fits the context best and will yield the best outcomes for both mother and child. For example, some of the guidelines included did not use a grading system for evidence or references when citing the recommendations (Diabetes Coalition of California, 2012;NGC, 2013;NICE, 2015;Permanente, 2018), while others did not use a grading system for the evidence included, but did use a variety of evidence when citing the recommendations (International Diabetes Federation, 2009;Queensland, 2015;SEMDSA, 2017;USPSTF, 2014

| Resources/Barriers
Only one guideline considered the context in terms of low/high resources (FIGO, 2015). The reality is that most low-resource countries are unable to implement some of the recommendations, such as, for example, universal 75-g OGTT or self-monitoring every day (FIGO, 2015 Kaiser and Razurel (2013) examined the determinants of health behaviours during the postpartum period in GDM patients. They found that the women's physical activity and diet do not often meet the recommended health-promoting actions. Risk perception, health beliefs, social support and self-efficacy were the main factors that were identified as having an impact on the adoption of health behaviours.

| Recommendations
GDM clients are encouraged to engage in lifestyle modifications or healthy behaviours during the postpartum period. It is important, therefore, to identify the factors that may influence these clients to continue with healthy behaviours (Kaiser & Razurel, 2013).
Education of the woman diagnosed with GDM on the screening, and management (including preventative lifestyles) is imperative and will assist in addressing some of the above-mentioned barriers.
Education, as mentioned by most guidelines, should preferably be given by nurses and/or midwives to all pregnant women that are at risk or diagnosed with GDM. Furthermore, the healthcare professionals will need to be trained on pregnancy-specific lifestyle mod- No contextualized guideline on the nursing management of GDM is available for contexts where women with GDM deal with specific challenges such as factors related to the health system, or socioeconomic and cultural conditions that may impose barriers to the implementation of the best practice. It is therefore recommended that, prior to the implementation, a context analysis should be conducted to identify specific barriers to its implementation. This was confirmed by FIGO (2015) who mentioned that local decisions will be required to decide whether a selective or universal approach will be used for each individual patient. Additionally, further research of the barriers is required to develop contextualized guidelines considering the challenges some women and some health systems may have in accessing or providing adequate maternal health care. The developed contextualized guidelines could then be piloted. Piloting will be done to determine how the guidelines could have a positive effect on the nursing management of GDM while considering the input from the pregnant women as well as possible barriers or resource constraints towards its implementation.

| Limitations
Some limitations of the study were observed. A comprehensive search of a variety of databases available to the authors was used with the assistance of an experienced librarian. However, limited databases were available, and some organizations/ developers of guidelines were not subscribed to so some guidelines may have been missed. Although the reviewer possessed wide experience in appraising the guidelines, more independent reviewers could have reduced possible bias in the selection process of the guidelines.

| CON CLUS ION
Data extracted from the eighteen guidelines resulted in two main themes: 1. Early screening and diagnosis of GDM; and 2. Nursing management of GDM (during pregnancy, intra-and postpartum management). Although a variety of guidelines on the management of GDM were found, guidelines were not always comprehensive, sometimes differed in recommended practices and did not consider barriers to the implementation of the recommendations.

| RELE VAN CE TO CLINI C AL PR AC TI CE
This study provides a summary of best practices regarding the diagnosis, screening and nursing management of GDM. The findings can be used by nurse-midwives when conducting maternal and postpartum follow-up care for women at risk or diagnosed with GDM. However, critically scrutinizing the guidelines in terms of the best evidence used in their development and feasibility of the implementation of the recommendations for its context is required.
Additionally, education of women with GDM could assist in addressing any barriers such as certain harmful health beliefs, a lack of social support and self-efficacy to provide the best maternal health care. Further research is recommended to determine the strength of evidence of each recommendation and the development and implementation of a contextual guideline on the management of GDM that considers possible barriers and resource constraints towards its implementation.

ACK N OWLED G EM ENTS
The authors would like to thank Vicki Igglesden for editing the manuscript.

CO N FLI C T O F I NTE R E S T
The authors have no conflicts of interest to disclose.