Prevention of gestational diabetes mellitus: a review of studies on weight management

Interaction of maternal smoking and gestational diabetes mellitus on newborn head circumference and birthweight

INTRODUCTION

Maternal smoking during pregnancy and gestational diabetes mellitus (GDM) have opposite effects on fetal growth during pregnancy. The aim of the study was to evaluate the interaction of smoking during pregnancy and gestational diabetes mellitus on head circumference and birthweight of newborns.

MATERIAL AND METHODS

The study included all primiparous women with singleton pregnancies (n = 290 602) without previously diagnosed diabetes or hypertension in Finland between 2006 and 2018. The information on gestational diabetes mellitus, newborn birthweight and head circumference, and maternal smoking and backgrounds was derived from the Finnish Medical Birth Register. Linear regression models were used in the analyses.

RESULTS

In total 8.0% of parturients quit smoking during the first trimester and 9.9% continued smoking thereafter. The prevalence of GDM was 8.9% (n = 25 948). Newborns of women who continued smoking had a smaller head circumference (b = -0.24, SE = 0.01, p < 0.0001) and birthweight (b = -0.28, SE = 0.01, p < 0.0001) compared to newborns of women who did not smoke. Head circumference and birthweight were greater in newborns of women with GDM (b = 0.09, SE = 0.01, p < 0.0001 and b = 0.16, SE = 0.01, p < 0.0001, respectively) compared to newborns of women without GDM. In the interaction analyses, head circumference (b = -0.13, SE = 0.01, p < 0.0001) was smaller and birthweight (b = -0.13, SE = 0.02, p < 0.0001) was lower in newborns of women with GDM who continued smoking compared to newborns of women without GDM who did not smoke.

CONCLUSIONS

Although smoking and GDM have opposite effects on fetal growth, the negative effects of exposure to smoking are also seen in newborns of women with GDM. Compared to smoking after the first trimester of pregnancy, cessation of smoking during the first trimester was associated with greater head circumference and birthweight in newborns.

Advances in free fatty acid profiles in gestational diabetes mellitus

The morbidity of gestational diabetes mellitus (GDM) is increasing and is associated with adverse perinatal outcomes and long-term maternal and infant health. The exact mechanism underlying changes in plasma free fatty acid (FFA) profiles in patients with GDM is unknown. However, it is believed that changes in diet and lipid metabolism may play a role. Fatty acids contain many specific FFAs, and the type of FFA has different impacts on physiological processes; hence, determining changes in FFAs in individual plasma is essential. Alterations in FFA concentration or profile may facilitate insulin resistance. Additionally, some FFAs show potential to predict GDM in early pregnancy and are strongly associated with the growth and development of the fetus and occurrence of macrosomia. Here, we aimed to review changes in FFAs in women with GDM and discuss the relationship of FFAs with GDM incidence and adverse outcomes.

Nutrients as Risk Factors and Treatments for Gestational Diabetes

Gestational diabetes (GDM), traditionally defined as any form of glucose intolerance first detected in pregnancy [...].

Risk Factors of Gestational Diabetes Mellitus Among Women Attending an Antenatal Care Clinic in Prince Sultan Military Medical City (PSMMC), Riyadh, Kingdom of Saudi Arabia: A Case-Control Study

BACKGROUND

Gestational diabetes mellitus (GDM) is a serious health issue for both mother and child. As GDM is common worldwide, healthcare providers pay attention while screening and managing pregnant women to ensure good outcomes for both mother and child.

OBJECTIVE

This study aims to identify the risk factors associated with developing GDM in pregnant women attending antenatal care clinics in Prince Sultan Military Medical City (PSMMC) in Riyadh, Saudi Arabia.

METHODS

This is a case-control study that utilized patients' medical records for data collection. The study included 317 pregnant Saudi women who attended antenatal care clinics and antenatal diabetic clinics in PSMMC from May 2022 to May 2023. Cases were defined as women who met the inclusion and exclusion criteria and had a positive oral glucose tolerance test (OGTT) result, while controls were defined as women in the same age group and gravidity who had negative OGTT. Analysis was conducted using SPSS Statistics version 29.0 (IBM Corp. Released 2021. IBM SPSS Statistics for Windows, Version 29.0. Armonk, NY: IBM Corp.) Results: The total number of cases was 132 out of 313 total samples, representing 42.2% of the total sample. Three factors were associated with an increased risk of developing GDM, including a family history of diabetes (p-value <0.001), a history of GDM (p-value <0.001), and macrosomia (p-value = 0.020). The study also found higher BMI and advanced maternal age were risk factors for GDM (p-value = 0.004, 0.007), respectively. However, the study did not find a significant association between GDM and other factors, such as chronic disease prevalence, history of miscarriage, or history of fetal death.

CONCLUSION

The study identified several risk factors associated with an increased risk of GDM including family history of diabetes, history of GDM, macrosomia, overweight/obesity, and advanced maternal age. It is recommended that antenatal care providers screen for GDM risk factors and closely monitor overweight, obese, or older women. Education and counseling on healthy lifestyle habits, such as maintaining a healthy weight and engaging in physical activity, may also be beneficial for preventing GDM. Further research is needed to confirm and identify additional risk factors for GDM.

Associations between plant-based diets, plant foods and botanical supplements with gestational diabetes mellitus: a systematic review protocol

INTRODUCTION

Gestational diabetes mellitus (GDM) is one of the most common health complications during pregnancy. Medical nutrition therapy is the mainstay of treatment for GDM, however, there is no current consensus on optimal dietary approaches to prevent or control hyperglycaemia in pregnancy. The aim of this systematic review is to assess the relationships between plant-based dietary patterns, plant foods and botanical dietary supplements with GDM and maternal glycaemic biomarkers.

METHODS AND ANALYSIS

A predefined search strategy was used on 16 June 2021, to search PubMed, Embase and CINAHL Plus with Full Text (EBSCOhost), as well as ClinicalTrials.gov, for studies published as original articles in English. Articles will be included if they are human observational studies or clinical trials and will be excluded if they are review articles or conference abstracts. We will use Cochrane's risk of bias tools for interventions that are parallel arm (Risk of Bias tool for randomised trials version 2 (RoB 2)) and single arm, non-randomised intervention studies (Risk of Bias In Non-randomised Studies-of Interventions (ROBINS-I)). For observational, case-control and cross-sectional studies, we will use the National Heart, Lung and Blood Institute's quality assessment tools. Data will be synthesised in a narrative format describing significant results as well as presenting the results of the quality assessment of studies.

ETHICS AND DISSEMINATION

This systematic review does not require ethical approval as primary data will not be collected. The review will be published in a peer-reviewed journal and disseminated electronically and in print.

PROSPERO REGISTRATION NUMBER

CRD42022306915.

A Clinical Update on Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) traditionally refers to abnormal glucose tolerance with onset or first recognition during pregnancy. GDM has long been associated with obstetric and neonatal complications primarily relating to higher infant birthweight and is increasingly recognized as a risk factor for future maternal and offspring cardiometabolic disease. The prevalence of GDM continues to rise internationally due to epidemiological factors including the increase in background rates of obesity in women of reproductive age and rising maternal age and the implementation of the revised International Association of the Diabetes and Pregnancy Study Groups' criteria and diagnostic procedures for GDM. The current lack of international consensus for the diagnosis of GDM reflects its complex historical evolution and pragmatic antenatal resource considerations given GDM is now 1 of the most common complications of pregnancy. Regardless, the contemporary clinical approach to GDM should be informed not only by its short-term complications but also by its longer term prognosis. Recent data demonstrate the effect of early in utero exposure to maternal hyperglycemia, with evidence for fetal overgrowth present prior to the traditional diagnosis of GDM from 24 weeks' gestation, as well as the durable adverse impact of maternal hyperglycemia on child and adolescent metabolism. The major contribution of GDM to the global epidemic of intergenerational cardiometabolic disease highlights the importance of identifying GDM as an early risk factor for type 2 diabetes and cardiovascular disease, broadening the prevailing clinical approach to address longer term maternal and offspring complications following a diagnosis of GDM.

Risk of gestational diabetes mellitus in relation to early pregnancy and gestational weight gain before diagnosis: A population-based cohort study

INTRODUCTION

Gestational diabetes mellitus (GDM) is a common pregnancy complication associated with adverse consequences for the mother and offspring in both short and long term. The aim of this study was to investigate associations between risk of GDM and gestational weight gain in early pregnancy and before diagnosis.

MATERIAL AND METHODS

Our population-based cohort study included 131 164 singleton pregnancies in the Stockholm-Gotland region in Sweden from 2008 through 2013. The exposures were weight gain in early pregnancy (<22 weeks) and weight gain before diagnosis, standardized into gestational age-specific z scores. The outcome was GDM. We used logistic regression models with a generalized estimating equations method to estimate odds ratios with 95% confidence intervals for GDM, stratified by early-pregnancy body mass index (BMI) category.

RESULTS

Above average weight gain before diagnosis (z score >0) was associated with increased risk of GDM among all BMI groups except for obese III. Early gestational weight gain above average was associated with increased risk for GDM in overweight women. Below average weight gain before diagnosis (z score <0) was only associated with decreased risk of GDM in obese III. Early gestational weight gain below average was associated with reduced risks of GDM in obese class I, II, and III women.

CONCLUSIONS

The risk of GDM increased with higher weight gain before diagnosis in all BMI groups except obese class III, whereas the risk was reduced with lower weight gain before diagnosis in obese III women only. The risk of GDM increased with higher early gestational weight gain in overweight women, while the risk was reduced with lower early gestational weight gain among obese women. Obese women may benefit from lower weight gain, especially in early pregnancy.

Role of ferritin and oxidative stress index in gestational diabetes mellitus

Objectives

To investigate the role of serum ferritin and oxidative stress in the development of GDM and to assess their relationship with the ensuing hyperglycemia.

Methods

A case-control study was carried on 90 non-anemic pregnant women of 20-40 years with a gestation of 24-28 weeks. Study group (n = 65) was identified according to the Diabetes in Pregnancy Study Group India (DIPSI) criteria (2-h plasma glucose ≥ 140 mg/dl) and controls (n = 25) having 2-h plasma glucose < 120 mg/dl. DIPSI 2-h plasma glucose, HbA1c and serum ferritin were measured and oxidative stress index (OSI) was calculated. Statistical tests were performed using SPSS version 25.0.

Results

Pre-pregnancy BMI showed a significant difference between control and study group. DIPSI 2 h blood glucose, HbA1c, serum ferritin and OSI were significantly higher in study group compared to control group. Both 2 h blood glucose and HbA1c were positively correlated with serum ferritin and OSI, serum ferritin and OSI were also positively correlated with each other.

Conclusion

Higher pre-pregnancy BMI elevates serum ferritin, which in turn increases the OSI. Both ferritin and oxidative stress raises 2 h blood glucose and HbA1c in GDM patients possibly by causing in-vivo pancreatic β -cell injury and death (ferroptosis). Serum ferritin and OSI could become newer personalized theranostic and monitoring targets in overweight/obese pregnant females especially GDM patients.

Nutrition as Prevention Factor of Gestational Diabetes Mellitus: A Narrative Review

Gestational diabetes mellitus (GDM) is defined as a glucose tolerance disorder with onset or first recognition during pregnancy. GDM is associated with several adverse maternal and neonatal outcomes. Management to reduce the incidence of GDM could decrease the incidence of these complications. Modification of nutrition in the prevention of GDM is postulated. The vital issue in GDM prevention is the implementation of proper dietary patterns, appropriate physical activity, and a combination of diet and lifestyle modifications. However, intervention studies examining the effects of diet and lifestyle on GDM prevention are contradictory. The aim of this study was to review the scientific evidence on nutritional prevention strategies, including diet and supplementation of some substances such as probiotics, micro/macroelements, fiber, myoinositol, and vitamins that may be effective in reducing the risk of GDM. The presented article is a narrative review. This article indicates that certain nutritional factors may have some benefit in preventing GDM. However, further studies in a variety of populations and large groups of patients are needed. At present, no definitive conclusions can be drawn as to the best intervention in the prevention of GDM.

The interaction between metabolic syndrome and physical activity, and risk for gestational diabetes mellitus

AIMS

Metabolic syndrome (MetS) is a cluster of risk factors which increases risk of cardiometabolic diseases in the adult population and increases risk for pregnancy complications such as gestational diabetes mellitus (GDM). Epidemiological data indicate that moderate-to-high levels of physical activity reduces the risk for GDM. The study aims to determine whether the association between MetS and GDM is affected by physical activity.

METHODS

We performed a prospective cohort study among 1373 pregnant nulliparous women in Adelaide, South Australia. At 9-16 weeks' gestation, demographic, lifestyle and self-reported frequencies of physical activity were obtained, and a non-fasting blood sample was taken for assessment of MetS, defined using the International Diabetes Federation criteria. GDM was diagnosed at 24-28 weeks' gestation using the World Health Organization classification.

RESULTS

1158 pregnant women were included: 107 (9%) women had MetS in early pregnancy, and 184 (16%) developed GDM. Having MetS increased the risk of developing GDM (37.4% vs. 13.7%, adjusted RR 2.5; 95% CI 1.7, 3.6). The interaction effect (RR; (95% CI) between MetS and physical activity was not significant (vigorous physical activity: 2.60; 0.46, 14.71) for ≥ 4 times per week; less vigorous activity; 0.77; 0.15, 4.02 for ≥ 4 times per week; stair climbing ≥ once day (1.16; 0.54, 2.51), all compared to no physical activity).

CONCLUSIONS

Physical activity was not an effect modifier in the association between GDM and MetS. Information collected about the nature and extent of physical activity needs to be more detailed and granular to determine whether physical activity really has an effect.

Adherence to Antidiabetic Medications among Women with Gestational Diabetes

BACKGROUND

Optimal adherence to prescribed medications in women with gestational diabetes is relevant for perinatal outcomes.

OBJECTIVE

To summarize available information on the prevalence and factors contributing to medication adherence in women with gestational diabetes from the biological and psychosocial perspectives.

METHODS

A literature search on adherence in gestational diabetes was conducted in PubMed/MEDLINE, CINAHL, Scopus, and the Directory of Open Access Journals for studies published on the topic. The Arksey and O'Malley framework for scoping reviews was used to explore and summarize the evidence.

RESULTS

A total of 2395 studies were retrieved of which 13 fully met the eligibility criteria. The studies were reported in Zimbabwe (n = 5), Iran (n = 1), Mexico (n = 1), South India (n = 1), the United States of America (n = 4), and one multinational study covering Australia, Europe, North and South America. The main types of antidiabetic medications used were insulin (n = 6), metformin (n = 4), and glyburide (n = 2). The prevalence of adherence ranged from 35.6% to 97%, with the assessment tool being self-report measures (n = 8). The main factors associated with nonadherence included worsening pregnancy symptoms, side effects of medications, perceived risks, mental health symptoms, poor social support, and socioeconomic status. Recommendations that evolved from the studies to improve adherence included education, counselling, improved support networks, and social interventions, while the main reported interventional study employed continuous education on the impact of adherence on perinatal outcomes.

CONCLUSION

Medication nonadherence in gestational diabetes seems to be influenced by multiple factors with some educational interventions positively impacting adherence behaviours. Thus, future research in women with gestational diabetes could consider interventions from a multifactorial perspective to improve therapeutic outcomes.

Food habits in pregnancy and its association with gestational diabetes mellitus: results from a prospective cohort study in public hospitals of urban India

Background

Few studies have explored the relationship between food habits and the risk of gestational diabetes mellitus (GDM) in women from India. We aimed to investigate the associations of food habits and the risk of GDM.

Methods

As part of the MAASTHI prospective cohort study in urban Bengaluru, India, pregnant women between 18 and 45 years, less than 36 weeks of gestation were included. During baseline, the participant’s age, education, physical activity levels, and food habits were recorded. Screening of GDM was done by the World Health Organization diagnostic criteria using a 2-h 75-g oral glucose tolerance test between the 24th–36th weeks of gestation.

Results

We included 1777 pregnant women in the study. We show that 17.6% of the women had GDM, of which 76.7% consume red meat. Red meat consumption was associated with an increased risk of GDM (aRR = 2.1, 95% CI 1.5, 2.9) after adjusting for age, family history of diabetes and socioeconomic status.

Conclusion

The high intake of red meat consumption in pregnancy needs further examination. Also, future evaluations should consider evaluating the risk of red meat consumption against the combined effect of inadequate consumption of vegetables, fruits, and dairy products in pregnant women. Interventions to educate women in lower socioeconomic status on inexpensive, seasonal, and healthy food might be helpful.

Gestational Diabetes Mellitus: A Harbinger of the Vicious Cycle of Diabetes

Gestational diabetes mellitus (GDM), characterized by a transitory form of diabetes induced by insulin resistance and pancreatic β-cell dysfunction during pregnancy, has been identified as one of the major obstacles in achieving improved maternal and child health. Approximately 9-25% of pregnancies worldwide are impacted by the acute, long-term, and transgenerational health complications of this disease. Here, we discuss how GDM affects longstanding maternal and neonatal outcomes, as well as health risks that likely persist into future generations. In addition to the current challenges in the management and diagnosis of and the complications associated with GDM, we discuss current preclinical models of GDM to better understand the underlying pathophysiology of the disease and the timely need to increase our scientific toolbox to identify strategies to prevent and treat GDM, thereby advancing clinical care.

Adherence to the Norwegian dietary recommendations in a multi-ethnic pregnant population prior to being diagnosed with gestational diabetes mellitus

Maternal diet is a modifiable risk factor for the development of gestational diabetes mellitus (GDM). Even though pregnant women are considered to be motivated to eat healthy, previous research found unhealthy eating patterns among some ethnic and lower socio-economic status groups. This cross-sectional study assessed adherence to national dietary recommendations prior to GDM diagnosis in a multi-ethnic population comprising 237 pregnant women. Participants were diagnosed with GDM after performing a two-hour oral glucose tolerance test ≥ 9 mmol/L. Participants answered a 41-item Food Frequency Questionnaire about dietary habits prior to being diagnosed with GDM from October 2015 to March 2018. Their scores were based on adherence to the recommended intake in each food group and summed into a Healthy Diet Score (HDS). Results showed low adherence to national dietary recommendations. A significantly higher proportion of non-native Norwegian-speaking women had a high HDS compared with native Norwegian-speaking women. Participants with a normal prepregnancy weight were more likely to have a high HDS compared with overweight or obese participants. Participants showed low adherence to the recommendations for whole grains, vegetables, and fruits and berries, and a relatively low proportion adhered to the recommendations for intakes of fish, red/processed meat, and ready-made meals. However, the food group intakes varied by country of birth. Given the increase in women with GDM and the emerging evidence that maternal diet is a modifiable risk factor for GDM, effective nutrition communication strategies in antenatal care are urgently needed.

Multistrain Probiotic Increases the Gut Microbiota Diversity in Obese Pregnant Women: Results from a Randomized, Double-Blind Placebo-Controlled Study

BACKGROUND

Maternal obesity is associated with adverse pregnancy outcomes. Probiotic supplementation during pregnancy may have positive effects on blood glucose, gestational weight gain (GWG), and the risk of gestational diabetes mellitus [GDM and glycated hemoglobin (HbA1c)].

OBJECTIVES

This feasibility study involved a daily probiotic intervention in obese pregnant women from the early second trimester until delivery. The primary aim was to investigate the effect on GWG and maternal glucose homeostasis (GDM and HbA1c). Secondary aims were the effect on infant birth weight, maternal gut microbiota, and other pregnancy outcomes.

METHODS

We carried out a randomized double-blinded placebo-controlled study in 50 obese pregnant women. Participants were randomly allocated (1:1) to multistrain probiotic (4 capsules of Vivomixx®; total of 450 billion CFU/d) or placebo at 14-20 weeks of gestation until delivery. Participants were followed with 2 predelivery visits at gestational week 27-30 and 36-37 and with 1 postdelivery visit. All visits included blood and fecal sampling. An oral-glucose-tolerance test was performed at inclusion and gestational week 27-30.

RESULTS

Forty-nine participants completed the study. Thirty-eight participants took >80% of the capsules (n = 21), placebo (n = 17). There was no significant difference in GWG, GDM, HbA1c concentrations, and infant birth weight between groups. Fecal microbiota analyses showed an overall increase in α-diversity over time in the probiotic group only (P = 0.016).

CONCLUSIONS

Administration of probiotics during pregnancy is feasible in obese women and the women were willing to participate in additional study visits and collection of fecal samples during pregnancy. Multistrain probiotic can modulate the gut microbiota in obese women during pregnancy. A larger study population is needed to uncover pregnancy effects after probiotic supplementation. This trial was registered at clincaltrials.gov as NCT02508844.

Interventions to prevent women from developing gestational diabetes mellitus: an overview of Cochrane Reviews

BACKGROUND

The prevalence of gestational diabetes mellitus (GDM) is increasing, with approximately 15% of pregnant women affected worldwide, varying by country, ethnicity and diagnostic thresholds. There are associated short- and long-term health risks for women and their babies.

OBJECTIVES

We aimed to summarise the evidence from Cochrane systematic reviews on the effects of interventions for preventing GDM.

METHODS

We searched the Cochrane Database of Systematic Reviews (6 August 2019) with key words 'gestational diabetes' OR 'GDM' to identify reviews pre-specifying GDM as an outcome. We included reviews of interventions in women who were pregnant or planning a pregnancy, irrespective of their GDM risk status. Two overview authors independently assessed eligibility, extracted data and assessed quality of evidence using ROBIS and GRADE tools. We assigned interventions to categories with graphic icons to classify the effectiveness of interventions as: clear evidence of benefit or harm (GRADE moderate- or high-quality evidence with a confidence interval (CI) that did not cross the line of no effect); clear evidence of no effect or equivalence (GRADE moderate- or high-quality evidence with a narrow CI crossing the line of no effect); possible benefit or harm (low-quality evidence with a CI that did not cross the line of no effect or GRADE moderate- or high-quality evidence with a wide CI); or unknown benefit or harm (GRADE low-quality evidence with a wide CI or very low-quality evidence).

MAIN RESULTS

We included 11 Cochrane Reviews (71 trials, 23,154 women) with data on GDM. Nine additional reviews pre-specified GDM as an outcome, but did not identify GDM data in included trials. Ten of the 11 reviews were judged to be at low risk of bias and one review at unclear risk of bias. Interventions assessed included diet, exercise, a combination of diet and exercise, dietary supplements, pharmaceuticals, and management of other health problems in pregnancy. The quality of evidence ranged from high to very low. Diet Unknown benefit or harm: there was unknown benefit or harm of dietary advice versus standard care, on the risk of GDM: risk ratio (RR) 0.60, 95% CI 0.35 to 1.04; 5 trials; 1279 women; very low-quality evidence. There was unknown benefit or harm of a low glycaemic index diet versus a moderate-high glycaemic index diet on the risk of GDM: RR 0.91, 95% CI 0.63 to 1.31; 4 trials; 912 women; low-quality evidence. Exercise Unknown benefit or harm: there was unknown benefit or harm for exercise interventions versus standard antenatal care on the risk of GDM: RR 1.10, 95% CI 0.66 to 1.84; 3 trials; 826 women; low-quality evidence. Diet and exercise combined Possible benefit: combined diet and exercise interventions during pregnancy versus standard care possibly reduced the risk of GDM: RR 0.85, 95% CI 0.71 to 1.01; 19 trials; 6633 women; moderate-quality evidence. Dietary supplements Clear evidence of no effect: omega-3 fatty acid supplementation versus none in pregnancy had no effect on the risk of GDM: RR 1.02, 95% CI 0.83 to 1.26; 12 trials; 5235 women; high-quality evidence. Possible benefit: myo-inositol supplementation during pregnancy versus control possibly reduced the risk of GDM: RR 0.43, 95% CI 0.29 to 0.64; 3 trials; 502 women; low-quality evidence. Possible benefit: vitamin D supplementation versus placebo or control in pregnancy possibly reduced the risk of GDM: RR 0.51, 95% CI 0.27 to 0.97; 4 trials; 446 women; low-quality evidence. Unknown benefit or harm: there was unknown benefit or harm of probiotic with dietary intervention versus placebo with dietary intervention (RR 0.37, 95% CI 0.15 to 0.89; 1 trial; 114 women; very low-quality evidence), or probiotic with dietary intervention versus control (RR 0.38, 95% CI 0.16 to 0.92; 1 trial; 111 women; very low-quality evidence) on the risk of GDM. There was unknown benefit or harm of vitamin D + calcium supplementation versus placebo (RR 0.33, 95% CI 0.01 to 7.84; 1 trial; 54 women; very low-quality evidence) or vitamin D + calcium + other minerals versus calcium + other minerals (RR 0.42, 95% CI 0.10 to 1.73; 1 trial; 1298 women; very low-quality evidence) on the risk of GDM. Pharmaceutical Possible benefit: metformin versus placebo given to obese pregnant women possibly reduced the risk of GDM: RR 0.85, 95% CI 0.61 to 1.19; 3 trials; 892 women; moderate-quality evidence. Unknown benefit or harm:eight small trials with low- to very low-quality evidence showed unknown benefit or harm for heparin, aspirin, leukocyte immunisation or IgG given to women with a previous stillbirth on the risk of GDM. Management of other health issues Clear evidence of no effect: universal versus risk based screening of pregnant women for thyroid dysfunction had no effect on the risk of GDM: RR 0.93, 95% CI 0.70 to 1.25; 1 trial; 4516 women; moderate-quality evidence. Unknown benefit or harm: there was unknown benefit or harm of using fractional exhaled nitrogen oxide versus a clinical algorithm to adjust asthma therapy on the risk of GDM: RR 0.74, 95% CI 0.31 to 1.77; 1 trial; 210 women; low-quality evidence. There was unknown benefit or harm of pharmacist led multidisciplinary approach to management of maternal asthma versus standard care on the risk of GDM: RR 5.00, 95% CI 0.25 to 99.82; 1 trial; 58 women; low-quality evidence.

AUTHORS' CONCLUSIONS

No interventions to prevent GDM in 11 systematic reviews were of clear benefit or harm. A combination of exercise and diet, supplementation with myo-inositol, supplementation with vitamin D and metformin were of possible benefit in reducing the risk of GDM, but further high-quality evidence is needed. Omega-3-fatty acid supplementation and universal screening for thyroid dysfunction did not alter the risk of GDM. There was insufficient high-quality evidence to establish the effect on the risk of GDM of diet or exercise alone, probiotics, vitamin D with calcium or other vitamins and minerals, interventions in pregnancy after a previous stillbirth, and different asthma management strategies in pregnancy. There is a lack of trials investigating the effect of interventions prior to or between pregnancies on risk of GDM.

Lactobacillus bulgaricus improves antioxidant capacity of black garlic in the prevention of gestational diabetes mellitus: a randomized control trial

Objectives:Lactobacillus bulgaricus may improve antioxidant capacity of black garlic in the prevention of gestational diabetes mellitus (GDM).

Methods: Black garlic was prepared with or without L. bulgaricus. Volatile and polysaccharides were analyzed by using LC-MS, Fourier Transform infrared (FTIR) and ¹³C nuclear magnetic resonance (NMR). The study design was parallel randomized controlled trial and 226 GDM patients were randomly assigned into BG (black garlic and L. bulgaricus) and CG (black garlic) groups, and allocation ratio was 1:1. The treatment duration was 40 weeks. Fasting blood glucose (FBG) and 1- and 2-h blood glucose (1hBG and 2hBG) after oral glucose tolerance test (OGTT) were detected. Antioxidant function of black garlic was determined by measuring plasma malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and total antioxidant capacity (T-AOC) in GDM patients. The comparison between two groups was made using two independent samples t test.

Results: The intake of nutrients was similar between two groups (P>0.05). L. bulgaricus promoted the transformation of the glucopyranoside to glucofuranoside. L. bulgaricus increased the abilities of black garlic for scavenging hydroxyl radicals, 2,2′-azino-bis (3-ethylbenzenthiazoline-6-sulfonic) acid (ABTS) and DPPH free radicals. L. bulgaricus reduced the levels of FBG, 1hBG and 2hBG, and incidence of perinatal complications (P<0.01). Plasma MDA level in the BG group was lower than in the CG group, whereas the levels of SOD, GSH-PX and T-AOC in the BG group were higher than in the CG group (P<0.01).

Conclusions:L. bulgaricus improves antioxidant capacity of black garlic in the prevention of GDM.

Interventions to prevent women developing gestational diabetes mellitus: an overview of Cochrane Reviews

This is a protocol for a Cochrane Review (Overview). The objectives are as follows:

To summarise the evidence from Cochrane systematic reviews regarding the effects of interventions to prevent women developing gestational diabetes mellitus (GDM).

The association between gestational diabetes mellitus and postpartum depressive symptomatology: A prospective cohort study

BACKGROUND

The literature suggests an association between type 2 diabetes mellitus and depression, but data on the association between gestational diabetes mellitus (GDM) and postpartum depressive symptomatology (PPDS) are scarce.

METHODS

Altogether, 1066 women with no previous mental health issues enrolled in the Kuopio Birth Cohort (KuBiCo, www.kubico.fi) were selected for this study. GDM was diagnosed according to the Finnish Current Care Guidelines. Depressive symptomatology was assessed with the Edinburgh Postnatal Depression Scale (EPDS) during the third trimester of pregnancy and eight weeks after delivery. Additionally, a subgroup of women (n = 505) also completed the EPDS during the first trimester of pregnancy.

RESULTS

The prevalence rates of GDM and PPDS in the whole study population were 14.1% and 10.3%, respectively. GDM was associated with an increased likelihood of belonging to the PPDS group (OR 2.23, 95% CI 1.23-4.05; adjusted for maternal age at delivery, BMI in the first trimester, smoking before pregnancy, relationship status, nulliparity, delivery by caesarean section, gestational age at delivery, neonatal intensive care unit admission and third-trimester EPDS scores). A significant association between GDM and PPDS was found in the subgroup of women with available data on first-trimester depression (n = 505).

LIMITATIONS

The participation rate of the KuBiCo study was relatively low (37%).

CONCLUSIONS

Women with GDM may be at increased risk of PPDS. Future studies should investigate whether these women would benefit from a closer follow-up and possible supportive interventions during pregnancy and the postpartum period to avoid PPDS.

Risk Factors for Gestational Diabetes Mellitus: A Case-Control Study

Background: The underlying causes of gestational diabetes mellitus (GDM) are important because they are effective for the diagnosis and prevention of this condition. The aim of this study was to identify the risk factors for GDM and the possible etiological agents. Materials and Methods: This case-control study was conducted with 100 women with GDM and 100 healthy pregnant women at a tertiary care hospital, affiliated to Babol University. GDM was identified by impaired oral glucose tolerance test based on the Carpenter and Coustan criteria. Healthy women were randomly selected from the prenatal health care clinic of the same center and were matched to gestational age of 24 to 28 weeks. Descriptive and inferential statistics were used for data analysis via the SPSS software. Results: After adjusting variables, multivariate analysis identified 4 significant risk factors of GDM, including prepregnancy low physical activity (odds ratio [OR] = 2.85, 95% confidence interval [CI]= 0.97-8.34), advanced maternal age (OR = 1.24, 95% CI = 1.13-1.35), body mass index ⩾ 30 kg/m² (OR = 1.10, 95% CI = 1.02-1.20), and family history of diabetes mellitus (OR = 5.62, 95% CI = 2.26-13.96). Conclusion: We observed significant associations between low prepregnancy physical activity and obesity with GDM risk. Thus the finding of this study can help devise strategies for the prevention of GDM.

Clinical significance of neuregulin 4 (NRG4) in gestational diabetes mellitus

OBJECTIVE

Gestational diabetes mellitus (GDM) is defined as glucose intolerance detected during pregnancy. GDM is increasing worldwide and is associated with adverse maternal and fetal outcomes. Neuregulin 4 (NGR4) is epidermal growth factor like signaling molecule. It plays an important role in cell to cell communication furthermore recent studies indicate that NRG4 may work as a novel adipokine with a possible role in maintaining energy and metabolic homeostasis. The aim of the present study was to assess serum NRG4 levels along with several metabolic parameters in patients diagnosed with gestational diabetic mellitus.

MATERIALS AND METHODS

In this prospective cross-sectional study, the study group was composed of 63 women with GDM and 64 healthy pregnant women matched for age, body mass index (BMI) and gestational age. Blood samples were collected at the 24-28th gestational weeks. Serum NRG4, total cholesterol, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides, glucose levels during 75-gr OGTT, fasting insulin, glycosylated hemoglobin A1c (HbA1c), alanine aminotransferase (ALT) and creatinine levels were measured. Homeostasis model assessment of insulin resistance (HOMA-IR) values were calculated.

RESULTS

Serum NRG4 values were significantly elevated in the GDM group compared to the control group (p < .001). Multivariate linear regression analyzes revealed that BMI (β = 0.910, p < .001), glucose 2-h OGTT (β = 0.866, p < .001) and HOMA-IR (β = 0.222, p < .001) independently and positively predicted NRG4 levels.

CONCLUSIONS

Serum NRG4 levels were associated with metabolic parameters of GDM. The present study can be considered to be a guide for future studies to clarify the pathophysiology of NGR4 in GDM patients.

Enablers and barriers to physical activity in overweight and obese pregnant women: an analysis informed by the theoretical domains framework and COM-B model

Background

Obesity during pregnancy is associated with increased risk of gestational diabetes mellitus (GDM) and other complications. Physical activity is a modifiable lifestyle factor that may help to prevent these complications but many women reduce their physical activity levels during pregnancy. Interventions targeting physical activity in pregnancy are on-going but few identify the underlying behaviour change mechanisms by which the intervention is expected to work. To enhance intervention effectiveness, recent tools in behavioural science such as the Theoretical Domains Framework (TDF) and COM-B model (capability, opportunity, motivation and behaviour) have been employed to understand behaviours for intervention development. Using these behaviour change methods, this study aimed to identify the enablers and barriers to physical activity in overweight and obese pregnant women.

Methods

Semi-structured interviews were conducted with a purposive sample of overweight and obese women at different stages of pregnancy attending a public antenatal clinic in a large academic maternity hospital in Cork, Ireland. Interviews were recorded and transcribed into NVivo V.10 software. Data analysis followed the framework approach, drawing on the TDF and the COM-B model.

Results

Twenty one themes were identified and these mapped directly on to the COM-B model of behaviour change and ten of the TDF domains. Having the social opportunity to engage in physical activity was identified as an enabler; pregnant women suggested being active was easier when supported by their partners. Knowledge was a commonly reported barrier with women lacking information on safe activities during pregnancy and describing the information received from their midwife as ‘limited’. Having the physical capability and physical opportunity to carry out physical activity were also identified as barriers; experiencing pain, a lack of time, having other children, and working prevented women from being active.

Conclusion

A wide range of barriers and enablers were identified which influenced women’s capability, motivation and opportunity to engage in physical activity with “knowledge” as the most commonly reported barrier. This study is a theoretical starting point in making a ‘behavioural diagnoses’ and the results will be used to inform the development of an intervention to increase physical activity levels among overweight and obese pregnant women.

Electronic supplementary material

The online version of this article (10.1186/s12884-018-1816-z) contains supplementary material, which is available to authorized users.

Combined diet and exercise interventions for preventing gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with a wide range of adverse health consequences for women and their infants in the short and long term. With an increasing prevalence of GDM worldwide, there is an urgent need to assess strategies for GDM prevention, such as combined diet and exercise interventions. This is an update of a Cochrane review that was first published in 2015.

OBJECTIVES

To assess the effects of diet interventions in combination with exercise interventions for pregnant women for preventing GDM, and associated adverse health consequences for the mother and her infant/child.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (27 November 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and cluster-RCTs, comparing combined diet and exercise interventions with no intervention (i.e. standard care), that reported on GDM diagnosis as an outcome. Quasi-RCTs were excluded. Cross-over trials were not eligible for inclusion. We planned to include RCTs comparing two or more different diet/exercise interventions, however none were identified.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data, assessed the risk of bias of the included trials and assessed quality of evidence for selected maternal and infant/child outcomes using the GRADE approach. We checked data for accuracy.

MAIN RESULTS

In this update, we included 23 RCTs (involving 8918 women and 8709 infants) that compared combined diet and exercise interventions with no intervention (standard care). The studies varied in the diet and exercise programs evaluated and health outcomes reported. None reported receiving funding from a drug manufacturer or agency with interests in the results. Overall risk of bias was judged to be unclear due to the lack of methodological detail reported. Most studies were undertaken in high-income countries.For our primary review outcomes, there was a possible reduced risk of GDM in the diet and exercise intervention group compared with the standard care group (average risk ratio (RR) 0.85, 95% confidence interval (CI) 0.71 to 1.01; 6633 women; 19 RCTs; Tau² = 0.05; I² = 42%; P = 0.07; moderate-quality evidence). There was also a possible reduced risk of caesarean section (RR 0.95, 95% CI 0.88 to 1.02; 6089 women; 14 RCTs; moderate-quality evidence). No clear differences were seen between groups for pre-eclampsia (RR 0.98, 95% CI 0.79 to 1.22; 5366 participants; 8 RCTs; low-quality evidence), pregnancy-induced hypertension and/or hypertension (average RR 0.78, 95% CI 0.47 to 1.27; 3073 participants; 6 RCTs; Tau² = 0.19; I² = 62%; very low-quality evidence), perinatal mortality (RR 0.82, 95% CI 0.42 to 1.63; 3757 participants; 2 RCTs; low-quality evidence) or large-for-gestational age (RR 0.93, 95% CI 0.81 to 1.07; 5353 participants; 11 RCTs; low-quality evidence). No data were reported for infant mortality or morbidity composite.Subgroup analyses (based on trial design, maternal body mass index (BMI) and ethnicity) revealed no clear differential treatment effects. We were unable to assess the impact of maternal age, parity and specific features of the diet and exercise interventions. Findings from sensitivity analyses (based on RCT quality) generally supported those observed in the main analyses. We were not able to perform subgroup analyses based on maternal age, parity or nature of the exercise/dietary interventions due to the paucity of information/data on these characteristics and the inability to meaningfully group intervention characteristics.For most of the secondary review outcomes assessed using GRADE, there were no clear differences between groups, including for perineal trauma (RR 1.27, 95% CI 0.78 to 2.05; 2733 participants; 2 RCTs; moderate-quality evidence), neonatal hypoglycaemia (average RR 1.42, 95% CI 0.67 to 2.98; 3653 participants; 2 RCTs; Tau² = 0.23; I² = 77%; low quality evidence); and childhood adiposity (BMI z score) (MD 0.05, 95% CI -0.29 to 0.40; 794 participants; 2 RCTs; Tau² = 0.04; I² = 59%; low-quality evidence). However, there was evidence of less gestational weight gain in the diet and exercise intervention group compared with the control group (mean difference (MD) -0.89 kg, 95% CI -1.39 to -0.40; 5052 women; 16 RCTs; Tau² = 0.37; I² = 43%;moderate-quality evidence). No data were reported for maternal postnatal depression or type 2 diabetes; childhood/adulthood type 2 diabetes, or neurosensory disability.

AUTHORS' CONCLUSIONS

Moderate-quality evidence suggests reduced risks of GDM and caesarean section with combined diet and exercise interventions during pregnancy as well as reductions in gestational weight gain, compared with standard care. There were no clear differences in hypertensive disorders of pregnancy, perinatal mortality, large-for-gestational age, perineal trauma, neonatal hypoglycaemia, and childhood adiposity (moderate- tovery low-quality evidence).Using GRADE methodology, the evidence was assessed as moderate to very low quality. Downgrading decisions were predominantly due to design limitations (risk of bias), and imprecision (uncertain effect estimates, and at times, small sample sizes and low event rates), however two outcomes (pregnancy-induced hypertension/hypertension and neonatal hypoglycaemia), were also downgraded for unexplained inconsistency (statistical heterogeneity).Due to the variability of the diet and exercise components tested in the included studies, the evidence in this review has limited ability to inform practice. Future studies could describe the interventions used in more detail, if and how these influenced behaviour change and ideally be standardised between studies. Studies could also consider using existing core outcome sets to facilitate more standardised reporting.

Insulin for the treatment of women with gestational diabetes

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with short- and long-term complications for the mother and her infant. Women who are unable to maintain their blood glucose concentration within pre-specified treatment targets with diet and lifestyle interventions will require anti-diabetic pharmacological therapies. This review explores the safety and effectiveness of insulin compared with oral anti-diabetic pharmacological therapies, non-pharmacological interventions and insulin regimens.

OBJECTIVES

To evaluate the effects of insulin in treating women with gestational diabetes.

SEARCH METHODS

We searched Pregnancy and Childbirth's Trials Register (1 May 2017), ClinicalTrials.gov, WHO International Clinical Trials Registry Platform (ICTRP) (1 May 2017) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (including those published in abstract form) comparing:a) insulin with an oral anti-diabetic pharmacological therapy;b) with a non-pharmacological intervention;c) different insulin analogues;d) different insulin regimens for treating women with diagnosed with GDM.We excluded quasi-randomised and trials including women with pre-existing type 1 or type 2 diabetes. Cross-over trials were not eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, risk of bias, and extracted data. Data were checked for accuracy.

MAIN RESULTS

We included 53 relevant studies (103 publications), reporting data for 7381 women. Forty-six of these studies reported data for 6435 infants but our analyses were based on fewer number of studies/participants.Overall, the risk of bias was unclear; 40 of the 53 included trials were not blinded. Overall, the quality of the evidence ranged from moderate to very low quality. The primary reasons for downgrading evidence were imprecision, risk of bias and inconsistency. We report the results for our maternal and infant GRADE outcomes for the main comparison. Insulin versus oral anti-diabetic pharmacological therapyFor the mother, insulin was associated with an increased risk for hypertensive disorders of pregnancy (not defined) compared to oral anti-diabetic pharmacological therapy (risk ratio (RR) 1.89, 95% confidence interval (CI) 1.14 to 3.12; four studies, 1214 women; moderate-quality evidence). There was no clear evidence of a difference between those who had been treated with insulin and those who had been treated with an oral anti-diabetic pharmacological therapy for the risk of pre-eclampsia (RR 1.14, 95% CI 0.86 to 1.52; 10 studies, 2060 women; moderate-quality evidence); the risk of birth by caesarean section (RR 1.03, 95% CI 0.93 to 1.14; 17 studies, 1988 women; moderate-quality evidence); or the risk of developing type 2 diabetes (metformin only) (RR 1.39, 95% CI 0.80 to 2.44; two studies, 754 women; moderate-quality evidence). The risk of undergoing induction of labour for those treated with insulin compared with oral anti-diabetic pharmacological therapy may possibly be increased, although the evidence was not clear (average RR 1.30, 95% CI 0.96 to 1.75; three studies, 348 women; I² = 32%; moderate-quality of evidence). There was no clear evidence of difference in postnatal weight retention between women treated with insulin and those treated with oral anti-diabetic pharmacological therapy (metformin) at six to eight weeks postpartum (MD -1.60 kg, 95% CI -6.34 to 3.14; one study, 167 women; low-quality evidence) or one year postpartum (MD -3.70, 95% CI -8.50 to 1.10; one study, 176 women; low-quality evidence). The outcomes of perineal trauma/tearing or postnatal depression were not reported in the included studies.For the infant, there was no evidence of a clear difference between those whose mothers had been treated with insulin and those treated with oral anti-diabetic pharmacological therapies for the risk of being born large-for-gestational age (average RR 1.01, 95% CI 0.76 to 1.35; 13 studies, 2352 infants; moderate-quality evidence); the risk of perinatal (fetal and neonatal death) mortality (RR 0.85; 95% CI 0.29 to 2.49; 10 studies, 1463 infants; low-quality evidence);, for the risk of death or serious morbidity composite (RR 1.03, 95% CI 0.84 to 1.26; two studies, 760 infants; moderate-quality evidence); the risk of neonatal hypoglycaemia (average RR 1.14, 95% CI 0.85 to 1.52; 24 studies, 3892 infants; low-quality evidence); neonatal adiposity at birth (% fat mass) (mean difference (MD) 1.6%, 95% CI -3.77 to 0.57; one study, 82 infants; moderate-quality evidence); neonatal adiposity at birth (skinfold sum/mm) (MD 0.8 mm, 95% CI -2.33 to 0.73; random-effects; one study, 82 infants; very low-quality evidence); or childhood adiposity (total percentage fat mass) (MD 0.5%; 95% CI -0.49 to 1.49; one study, 318 children; low-quality evidence). Low-quality evidence also found no clear differences between groups for rates of neurosensory disabilities in later childhood: hearing impairment (RR 0.31, 95% CI 0.01 to 7.49; one study, 93 children), visual impairment (RR 0.31, 95% CI 0.03 to 2.90; one study, 93 children), or any mild developmental delay (RR 1.07, 95% CI 0.33 to 3.44; one study, 93 children). Later infant mortality, and childhood diabetes were not reported as outcomes in the included studies.We also looked at comparisons for regular human insulin versus other insulin analogues, insulin versus diet/standard care, insulin versus exercise and comparisons of insulin regimens, however there was insufficient evidence to determine any differences for many of the key health outcomes. Please refer to the main results for more information about these comparisons.

AUTHORS' CONCLUSIONS

The main comparison in this review is insulin versus oral anti-diabetic pharmacological therapies. Insulin and oral anti-diabetic pharmacological therapies have similar effects on key health outcomes. The quality of the evidence ranged from very low to moderate, with downgrading decisions due to imprecision, risk of bias and inconsistency.For the other comparisons of this review (insulin compared with non-pharmacological interventions, different insulin analogies or different insulin regimens), there is insufficient volume of high-quality evidence to determine differences for key health outcomes.Long-term maternal and neonatal outcomes were poorly reported for all comparisons.The evidence suggests that there are minimal harms associated with the effects of treatment with either insulin or oral anti-diabetic pharmacological therapies. The choice to use one or the other may be down to physician or maternal preference, availability or severity of GDM. Further research is needed to explore optimal insulin regimens. Further research could aim to report data for standardised GDM outcomes.

National study of the prevalence of gestational diabetes mellitus among Danish women from 2004 to 2012

AIMS

The prevalence of gestational diabetes mellitus (GDM) is increasing worldwide. We studied the prevalence of GDM from 2004 to 2012 in Danish women aged 15-49 years using registries with records of the diagnosis of GDM at delivery.

METHODS

We conducted a national register-based study of 12,538 women with a diagnosis of GDM during a pregnancy leading to a live birth in the period 2004-2012. The diagnosis of GDM was taken from the National Patient Registry and combined with the total number of births at the national level from Statistics Denmark. Prevalence estimates were reported as crude and age-standardized using Danish and international data for women aged 15-49 years.

RESULTS

A total of 566,083 live births was registered in Denmark from 2004 to 2012. The age-standardized prevalence of GDM increased from 1.7% (1095/63,465) of the total births in 2004 to 2.9% (1721/56,894) of the total births in 2012. During the period 2004-2012, the age-stratified prevalence increased from 1.1 to 1.8% among women aged 15-24 years, from 1.5 to 2.6% among women aged 25-34 years and from 2.9 to 4.7% among women aged 35-49 years. The prevalence was higher among immigrants and their descendants than in native Danish women (4.06 and 2.09% in 2007 vs. 4.51 and 2.72% in 2012, respectively).

CONCLUSIONS

The prevalence of GDM in Denmark has increased across all age groups. Although the prevalence is low on a global scale, attention should be paid to this development by preventive health services.

Serum chemerin level during the first trimester of pregnancy and the risk of gestational diabetes mellitus

OBJECTIVE

To investigate the association between chemerin level in the first trimester of pregnancy and the risk of gestational diabetes mellitus.

METHODS

The blood samples of 212 women at 8-12 weeks of gestation were collected. After screening for gestational diabetes mellitus (GDM), 19 women with GDM and 20 women randomly selected from 144 women with normal glucose tolerance (NGT) were included in the study. Blood samples were collected from these women. Triglycerides, glucose, total cholesterol, and HDL cholesterol, LDL cholesterol, insulin and chemerin were measured. Gestational weight gain and body mass index was assessed.

RESULTS

Serum levels of chemerin were significantly elevated during late gestation, and the risk of GDM was positively associated with maternal serum chemerin in the first trimester.

CONCLUSION

Serum chemerin level during the first trimester of pregnancy has the potential to predict risk of GDM.

Lifestyle interventions for the treatment of women with gestational diabetes

BACKGROUND

Gestational diabetes (GDM) is glucose intolerance, first recognised in pregnancy and usually resolving after birth. GDM is associated with both short- and long-term adverse effects for the mother and her infant. Lifestyle interventions are the primary therapeutic strategy for many women with GDM.

OBJECTIVES

To evaluate the effects of combined lifestyle interventions with or without pharmacotherapy in treating women with gestational diabetes.

SEARCH METHODS

We searched the Pregnancy and Childbirth Group's Trials Register (14 May 2016), ClinicalTrials.gov, WHO International Clinical Trials Registry Platform (ICTRP) (14th May 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

We included only randomised controlled trials comparing a lifestyle intervention with usual care or another intervention for the treatment of pregnant women with GDM. Quasi-randomised trials were excluded. Cross-over trials were not eligible for inclusion. Women with pre-existing type 1 or type 2 diabetes were excluded.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by the Cochrane Collaboration. All selection of studies, data extraction was conducted independently by two review authors.

MAIN RESULTS

Fifteen trials (in 45 reports) are included in this review (4501 women, 3768 infants). None of the trials were funded by a conditional grant from a pharmaceutical company. The lifestyle interventions included a wide variety of components such as education, diet, exercise and self-monitoring of blood glucose. The control group included usual antenatal care or diet alone. Using GRADE methodology, the quality of the evidence ranged from high to very low quality. The main reasons for downgrading evidence were inconsistency and risk of bias. We summarised the following data from the important outcomes of this review. Lifestyle intervention versus control groupFor the mother:There was no clear evidence of a difference between lifestyle intervention and control groups for the risk of hypertensive disorders of pregnancy (pre-eclampsia) (average risk ratio (RR) 0.70; 95% confidence interval (CI) 0.40 to 1.22; four trials, 2796 women; I² = 79%, Tau² = 0.23; low-quality evidence); caesarean section (average RR 0.90; 95% CI 0.78 to 1.05; 10 trials, 3545 women; I² = 48%, Tau² = 0.02; low-quality evidence); development of type 2 diabetes (up to a maximum of 10 years follow-up) (RR 0.98, 95% CI 0.54 to 1.76; two trials, 486 women; I² = 16%; low-quality evidence); perineal trauma/tearing (RR 1.04, 95% CI 0.93 to 1.18; one trial, n = 1000 women; moderate-quality evidence) or induction of labour (average RR 1.20, 95% CI 0.99 to 1.46; four trials, n = 2699 women; I² = 37%; high-quality evidence).More women in the lifestyle intervention group had met postpartum weight goals one year after birth than in the control group (RR 1.75, 95% CI 1.05 to 2.90; 156 women; one trial, low-quality evidence). Lifestyle interventions were associated with a decrease in the risk of postnatal depression compared with the control group (RR 0.49, 95% CI 0.31 to 0.78; one trial, n = 573 women; low-quality evidence).For the infant/child/adult:Lifestyle interventions were associated with a reduction in the risk of being born large-for-gestational age (LGA) (RR 0.60, 95% CI 0.50 to 0.71; six trials, 2994 infants; I² = 4%; moderate-quality evidence). Birthweight and the incidence of macrosomia were lower in the lifestyle intervention group.Exposure to the lifestyle intervention was associated with decreased neonatal fat mass compared with the control group (mean difference (MD) -37.30 g, 95% CI -63.97 to -10.63; one trial, 958 infants; low-quality evidence). In childhood, there was no clear evidence of a difference between groups for body mass index (BMI) ≥ 85th percentile (RR 0.91, 95% CI 0.75 to 1.11; three trials, 767 children; I² = 4%; moderate-quality evidence).There was no clear evidence of a difference between lifestyle intervention and control groups for the risk of perinatal death (RR 0.09, 95% CI 0.01 to 1.70; two trials, 1988 infants; low-quality evidence). Of 1988 infants, only five events were reported in total in the control group and there were no events in the lifestyle group. There was no clear evidence of a difference between lifestyle intervention and control groups for a composite of serious infant outcome/s (average RR 0.57, 95% CI 0.21 to 1.55; two trials, 1930 infants; I² = 82%, Tau² = 0.44; very low-quality evidence) or neonatal hypoglycaemia (average RR 0.99, 95% CI 0.65 to 1.52; six trials, 3000 infants; I² = 48%, Tau² = 0.12; moderate-quality evidence). Diabetes and adiposity in adulthood and neurosensory disability in later childhoodwere not prespecified or reported as outcomes for any of the trials included in this review.

AUTHORS' CONCLUSIONS

Lifestyle interventions are the primary therapeutic strategy for women with GDM. Women receiving lifestyle interventions were less likely to have postnatal depression and were more likely to achieve postpartum weight goals. Exposure to lifestyle interventions was associated with a decreased risk of the baby being born LGA and decreased neonatal adiposity. Long-term maternal and childhood/adulthood outcomes were poorly reported.The value of lifestyle interventions in low-and middle-income countries or for different ethnicities remains unclear. The longer-term benefits or harms of lifestyle interventions remains unclear due to limited reporting.The contribution of individual components of lifestyle interventions could not be assessed. Ten per cent of participants also received some form of pharmacological therapy. Lifestyle interventions are useful as the primary therapeutic strategy and most commonly include healthy eating, physical activity and self-monitoring of blood glucose concentrations.Future research could focus on which specific interventions are most useful (as the sole intervention without pharmacological treatment), which health professionals should give them and the optimal format for providing the information. Evaluation of long-term outcomes for the mother and her child should be a priority when planning future trials. There has been no in-depth exploration of the costs 'saved' from reduction in risk of LGA/macrosomia and potential longer-term risks for the infants.

Antidiabetic Activity of a Lotus Leaf Selenium (Se)-Polysaccharide in Rats with Gestational Diabetes Mellitus

A selenium (Se)-containing polysaccharide, lotus leaf selenium (Se)-polysaccharide (LLP), was isolated from a lotus leaf. The effects of LLP on antioxidant enzyme activities and insulin resistance in pregnant rats with gestational diabetes mellitus (GDM) were investigated. LLP administered orally at two doses (50 and 100 mg/kg) could significantly reverse the weight loss of pregnant rats before the delivery, fetal rats, and placentas in GDM rats (P < 0.05). Furthermore, LLP treatment induced a decrease of fasting blood glucose (FBG) and fasting blood insulin (FINS) levels in GDM rats, but an increase of hepatic glycogen content, when compared with those in GDM rats (P < 0.05). Also, oral administrations of LLP markedly improved the lipid profile of GDM rats, as evidenced by a reduction of total cholesterol (TC), triglyceride (TG), and low-density lipoprotein (LDL) cholesterol levels except for the high-density lipoprotein (HDL) cholesterol level. Additionally, antioxidant enzyme levels, such as superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), and glutathione (GSH), in liver tissues of the GDM group were lower than those of the other groups, and following treatment of LLP, these indexes in liver tissues were equivalent to those of the control group (P > 0.05). All the data indicated that LLP may be a promising drug candidate or a healthcare food for GDM therapy or protection.

Different types of dietary advice for women with gestational diabetes mellitus

BACKGROUND

Dietary advice is the main strategy for managing gestational diabetes mellitus (GDM). It remains unclear what type of advice is best.

OBJECTIVES

To assess the effects of different types of dietary advice for women with GDM for improving health outcomes for women and babies.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (8 March 2016), PSANZ's Trials Registry (22 March 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials comparing the effects of different types of dietary advice for women with GDM.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility, risk of bias, and extracted data. Evidence quality for two comparisons was assessed using GRADE, for primary outcomes for the mother: hypertensive disorders of pregnancy; caesarean section; type 2 diabetes mellitus; and child: large-for-gestational age; perinatal mortality; neonatal mortality or morbidity composite; neurosensory disability; secondary outcomes for the mother: induction of labour; perineal trauma; postnatal depression; postnatal weight retention or return to pre-pregnancy weight; and child: hypoglycaemia; childhood/adulthood adiposity; childhood/adulthood type 2 diabetes mellitus.

MAIN RESULTS

In this update, we included 19 trials randomising 1398 women with GDM, at an overall unclear to moderate risk of bias (10 comparisons). For outcomes assessed using GRADE, downgrading was based on study limitations, imprecision and inconsistency. Where no findings are reported below for primary outcomes or pre-specified GRADE outcomes, no data were provided by included trials. Primary outcomes Low-moderate glycaemic index (GI) versus moderate-high GI diet (four trials): no clear differences observed for: large-for-gestational age (risk ratio (RR) 0.71, 95% confidence interval (CI) 0.22 to 2.34; two trials, 89 infants; low-quality evidence); severe hypertension or pre-eclampsia (RR 1.02, 95% CI 0.07 to 15.86; one trial, 95 women; very low-quality evidence); eclampsia (RR 0.34, 95% CI 0.01 to 8.14; one trial, 83 women; very low-quality evidence) or caesarean section (RR 0.66, 95% CI 0.29 to 1.47; one trial, 63 women; low-quality evidence). Energy-restricted versus no energy-restricted diet (three trials): no clear differences seen for: large-for-gestational age (RR 1.17, 95% CI 0.65 to 2.12; one trial, 123 infants; low-quality evidence); perinatal mortality (no events; two trials, 423 infants; low-quality evidence); pre-eclampsia (RR 1.00, 95% CI 0.51 to 1.97; one trial, 117 women; low-quality evidence); or caesarean section (RR 1.12, 95% CI 0.80 to 1.56; two trials, 420 women; low-quality evidence). DASH (Dietary Approaches to Stop Hypertension) diet versus control diet (three trials): no clear differences observed for: pre-eclampsia (RR 1.00, 95% CI 0.31 to 3.26; three trials, 136 women); however there were fewer caesarean sections in the DASH diet group (RR 0.53, 95% CI 0.37 to 0.76; two trials, 86 women). Low-carbohydrate versus high-carbohydrate diet (two trials): no clear differences seen for: large-for-gestational age (RR 0.51, 95% CI 0.13 to 1.95; one trial, 149 infants); perinatal mortality (RR 3.00, 95% CI 0.12 to 72.49; one trial, 150 infants); maternal hypertension (RR 0.40, 95% CI 0.13 to 1.22; one trial, 150 women); or caesarean section (RR 1.29, 95% CI 0.84 to 1.99; two trials, 179 women). High unsaturated fat versus low unsaturated fat diet (two trials): no clear differences observed for: large-for-gestational age (RR 0.54, 95% CI 0.21 to 1.37; one trial, 27 infants); pre-eclampsia (no cases; one trial, 27 women); hypertension in pregnancy (RR 0.54, 95% CI 0.06 to 5.26; one trial, 27 women); caesarean section (RR 1.08, 95% CI 0.07 to 15.50; one trial, 27 women); diabetes at one to two weeks (RR 2.00, 95% CI 0.45 to 8.94; one trial, 24 women) or four to 13 months postpartum (RR 1.00, 95% CI 0.10 to 9.61; one trial, six women). Low-GI versus high-fibre moderate-GI diet (one trial): no clear differences seen for: large-for-gestational age (RR 2.87, 95% CI 0.61 to 13.50; 92 infants); caesarean section (RR 1.91, 95% CI 0.91 to 4.03; 92 women); or type 2 diabetes at three months postpartum (RR 0.76, 95% CI 0.11 to 5.01; 58 women). Diet recommendation plus diet-related behavioural advice versus diet recommendation only (one trial): no clear differences observed for: large-for-gestational age (RR 0.73, 95% CI 0.25 to 2.14; 99 infants); or caesarean section (RR 0.78, 95% CI 0.38 to 1.62; 99 women). Soy protein-enriched versus no soy protein diet (one trial): no clear differences seen for: pre-eclampsia (RR 2.00, 95% CI 0.19 to 21.03; 68 women); or caesarean section (RR 1.00, 95% CI 0.57 to 1.77; 68 women). High-fibre versus standard-fibre diet (one trial): no primary outcomes reported. Ethnic-specific versus standard healthy diet (one trial): no clear differences observed for: large-for-gestational age (RR 0.14, 95% CI 0.01 to 2.45; 20 infants); neonatal composite adverse outcome (no events; 20 infants); gestational hypertension (RR 0.33, 95% CI 0.02 to 7.32; 20 women); or caesarean birth (RR 1.20, 95% CI 0.54 to 2.67; 20 women). Secondary outcomes For secondary outcomes assessed using GRADE no differences were observed: between a low-moderate and moderate-high GI diet for induction of labour (RR 0.88, 95% CI 0.33 to 2.34; one trial, 63 women; low-quality evidence); or an energy-restricted and no energy-restricted diet for induction of labour (RR 1.02, 95% CI 0.68 to 1.53; one trial, 114 women, low-quality evidence) and neonatal hypoglycaemia (average RR 1.06, 95% CI 0.48 to 2.32; two trials, 408 infants; very low-quality evidence).Few other clear differences were observed for reported outcomes. Longer-term health outcomes and health services use and costs were largely not reported.

AUTHORS' CONCLUSIONS

Evidence from 19 trials assessing different types of dietary advice for women with GDM suggests no clear differences for primary outcomes and secondary outcomes assessed using GRADE, except for a possible reduction in caesarean section for women receiving a DASH diet compared with a control diet. Few differences were observed for secondary outcomes.Current evidence is limited by the small number of trials in each comparison, small sample sizes, and variable methodological quality. More evidence is needed to assess the effects of different types of dietary advice for women with GDM. Future trials should be adequately powered to evaluate short- and long-term outcomes.

Alterations of fatty acid profiles in gestational diabetes and influence of the diet

Gestational diabetes mellitus (GDM) is a pregnancy-induced complication with increased prevalence, especially in overweight women. Fatty acid (FA) composition in tissues can reflect dietary fat intake, especially essential FA intake. Moreover, it has been shown that FA profiles in blood lipid fractions are altered in diabetic patients. Consequently, women with GDM may also have a distinctive FA profile. The objective of this review is compare FA profiles in different blood lipid fractions and the influence of dietary fat intake in women with GDM or normoglycemic pregnancies. Results show that women with GDM have more saturated and less polyunsaturated FA (PUFA) in their red blood cell (RBC) membranes than normoglycemic pregnant women. Moreover, some studies reported that women with GDM have a greater energy intake from total fat and saturated FA, along with a lower energy intake from PUFA, when compared to normoglycemic pregnancies. Clinical trials showed that omega-3 PUFA levels in RBC membranes of GDM women can be restored by a dietary intervention. Further research is required to determine whether FA profiles are altered prior to the diagnosis of GDM and can be prevented by diet.

Oral anti-diabetic pharmacological therapies for the treatment of women with gestational diabetes

BACKGROUND

Gestational diabetes mellitus (GDM) is a major public health issue with rates increasing globally. Gestational diabetes, glucose intolerance first recognised during pregnancy, usually resolves after birth and is associated with short- and long-term complications for the mother and her infant. Treatment options can include oral anti-diabetic pharmacological therapies.

OBJECTIVES

To evaluate the effects of oral anti-diabetic pharmacological therapies for treating women with GDM.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (14 May 2016), ClinicalTrials.gov, WHO ICTRP (14 May 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

We included published and unpublished randomised controlled trials assessing the effects of oral anti-diabetic pharmacological therapies for treating pregnant women with GDM. We included studies comparing oral anti-diabetic pharmacological therapies with 1) placebo/standard care, 2) another oral anti-diabetic pharmacological therapy, 3) combined oral anti-diabetic pharmacological therapies. Trials using insulin as the comparator were excluded as they are the subject of a separate Cochrane systematic review.Women with pre-existing type 1 or type 2 diabetes were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and trial quality. Two review authors independently extracted data and data were checked for accuracy.

MAIN RESULTS

We included 11 studies (19 publications) (1487 women and their babies). Eight studies had data that could be included in meta-analyses. Studies were conducted in Brazil, India, Israel, UK, South Africa and USA. The studies varied in diagnostic criteria and treatment targets for glycaemic control for GDM. The overall risk of bias was 'unclear' due to inadequate reporting of methodology. Using GRADE the quality of the evidence ranged from moderate to very low quality. Evidence was downgraded for risk of bias (reporting bias, lack of blinding), inconsistency, indirectness, imprecision and for oral anti-diabetic therapy versus placebo for generalisability. Oral anti-diabetic pharmacological therapies versus placebo/standard careThere was no evidence of a difference between glibenclamide and placebo groups for hypertensive disorders of pregnancy (risk ratio (RR) 1.24, 95% confidence interval (CI) 0.81 to 1.90; one study, 375 women, very low-quality evidence), birth by caesarean section (RR 1.03, 95% CI 0.79 to 1.34; one study, 375 women, very low-quality evidence), perineal trauma (RR 0.98, 95% CI 0.06 to 15.62; one study, 375 women, very low-quality evidence) or induction of labour (RR 1.18, 95% CI 0.79 to 1.76; one study, 375 women; very low-quality evidence). No data were reported for development of type 2 diabetes or other pre-specified GRADE maternal outcomes (return to pre-pregnancy weight, postnatal depression). For the infant, there was no evidence of a difference in the risk of being born large-for-gestational age (LGA) between infants whose mothers had been treated with glibenclamide and those in the placebo group (RR 0.89, 95% CI 0.51 to 1.58; one study, 375, low-quality evidence). No data were reported for other infant primary or GRADE outcomes (perinatal mortality, death or serious morbidity composite, neurosensory disability in later childhood, neonatal hypoglycaemia, adiposity, diabetes). Metformin versus glibenclamideThere was no evidence of a difference between metformin- and glibenclamide-treated groups for the risk of hypertensive disorders of pregnancy (RR 0.70, 95% CI 0.38 to 1.30; three studies, 508 women, moderate-quality evidence), birth by caesarean section (average RR 1.20, 95% CI 1.20; 95% CI 0.83 to 1.72, four studies, 554 women, I2 = 61%, Tau2 = 0.07 low-quality evidence), induction of labour (0.81, 95% CI 0.61 to 1.07; one study, 159 women; low-quality evidence) or perineal trauma (RR 1.67, 95% CI 0.22 to 12.52; two studies, 158 women; low-quality evidence). No data were reported for development of type 2 diabetes or other pre-specified GRADE maternal outcomes (return to pre-pregnancy weight, postnatal depression). For the infant there was no evidence of a difference between the metformin- and glibenclamide-exposed groups for the risk of being born LGA (average RR 0.67, 95% CI 0.24 to 1.83; two studies, 246 infants, I2 = 54%, Tau2 = 0.30 low-quality evidence). Metformin was associated with a decrease in a death or serious morbidity composite (RR 0.54, 95% CI 0.31 to 0.94; one study, 159 infants, low-quality evidence). There was no clear difference between groups for neonatal hypoglycaemia (RR 0.86, 95% CI 0.42 to 1.77; four studies, 554 infants, low-quality evidence) or perinatal mortality (RR 0.92, 95% CI 0.06 to 14.55, two studies, 359 infants). No data were reported for neurosensory disability in later childhood or for adiposity or diabetes. Glibenclamide versus acarboseThere was no evidence of a difference between glibenclamide and acarbose from one study (43 women) for any of their maternal or infant primary outcomes (caesarean section, RR 0.95, 95% CI 0.53 to 1.70; low-quality evidence; perinatal mortality - no events; low-quality evidence; LGA , RR 2.38, 95% CI 0.54 to 10.46; low-quality evidence). There was no evidence of a difference between glibenclamide and acarbose for neonatal hypoglycaemia (RR 6.33, 95% CI 0.87 to 46.32; low-quality evidence). There were no data reported for other pre-specified GRADE or primary maternal outcomes (hypertensive disorders of pregnancy, development of type 2 diabetes, perineal trauma, return to pre-pregnancy weight, postnatal depression, induction of labour) or neonatal outcomes (death or serious morbidity composite, adiposity or diabetes).

AUTHORS' CONCLUSIONS

There were insufficient data comparing oral anti-diabetic pharmacological therapies with placebo/standard care (lifestyle advice) to inform clinical practice. There was insufficient high-quality evidence to be able to draw any meaningful conclusions as to the benefits of one oral anti-diabetic pharmacological therapy over another due to limited reporting of data for the primary and secondary outcomes in this review. Short- and long-term clinical outcomes for this review were inadequately reported or not reported. Current choice of oral anti-diabetic pharmacological therapy appears to be based on clinical preference, availability and national clinical practice guidelines.The benefits and potential harms of one oral anti-diabetic pharmacological therapy compared with another, or compared with placebo/standard care remains unclear and requires further research. Future trials should attempt to report on the core outcomes suggested in this review, in particular long-term outcomes for the woman and the infant that have been poorly reported to date, women's experiences and cost benefit.

Dietary advice interventions in pregnancy for preventing gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) is a form of diabetes occurring during pregnancy which can result in short- and long-term adverse outcomes for women and babies. With an increasing prevalence worldwide, there is a need to assess strategies, including dietary advice interventions, that might prevent GDM.

OBJECTIVES

To assess the effects of dietary advice interventions for preventing GDM and associated adverse health outcomes for women and their babies.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (3 January 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs assessing the effects of dietary advice interventions compared with no intervention (standard care), or to different dietary advice interventions. Cluster-RCTs were eligible for inclusion but none were identified.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of the included studies. Data were checked for accuracy. The quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

We included 11 trials involving 2786 women and their babies, with an overall unclear to moderate risk of bias. Six trials compared dietary advice interventions with standard care; four compared low glycaemic index (GI) with moderate- to high-GI dietary advice; one compared specific (high-fibre focused) with standard dietary advice. Dietary advice interventions versus standard care (six trials) Considering primary outcomes, a trend towards a reduction in GDM was observed for women receiving dietary advice compared with standard care (average risk ratio (RR) 0.60, 95% confidence interval (CI) 0.35 to 1.04; five trials, 1279 women; Tau² = 0.20; I² = 56%; P = 0.07; GRADE: very low-quality evidence); subgroup analysis suggested a greater treatment effect for overweight and obese women receiving dietary advice. While no clear difference was observed for pre-eclampsia (RR 0.61, 95% CI 0.25 to 1.46; two trials, 282 women; GRADE: low-quality evidence) a reduction in pregnancy-induced hypertension was observed for women receiving dietary advice (RR 0.30, 95% CI 0.10 to 0.88; two trials, 282 women; GRADE: low-quality evidence). One trial reported on perinatal mortality, and no deaths were observed (GRADE: very low-quality evidence). None of the trials reported on large-for-gestational age or neonatal mortality and morbidity.For secondary outcomes, no clear differences were seen for caesarean section (average RR 0.98, 95% CI 0.78 to 1.24; four trials, 1194 women; Tau² = 0.02; I² = 36%; GRADE: low-quality evidence) or perineal trauma (RR 0.83, 95% CI 0.23 to 3.08; one trial, 759 women; GRADE: very low-quality evidence). Women who received dietary advice gained less weight during pregnancy (mean difference (MD) -4.70 kg, 95% CI -8.07 to -1.34; five trials, 1336 women; Tau² = 13.64; I² = 96%; GRADE: low-quality evidence); the result should be interpreted with some caution due to considerable heterogeneity. No clear differences were seen for the majority of secondary outcomes reported, including childhood/adulthood adiposity (skin-fold thickness at six months) (MD -0.10 mm, 95% CI -0.71 to 0.51; one trial, 132 children; GRADE: low-quality evidence). Women receiving dietary advice had a lower well-being score between 14 and 28 weeks, more weight loss at three months, and were less likely to have glucose intolerance (one trial).The trials did not report on other secondary outcomes, particularly those related to long-term health and health service use and costs. We were not able to assess the following outcomes using GRADE: postnatal depression; maternal type 2 diabetes; neonatal hypoglycaemia; childhood/adulthood type 2 diabetes; and neurosensory disability. Low-GI dietary advice versus moderate- to high-GI dietary advice (four trials) Considering primary outcomes, no clear differences were shown in the risks of GDM (RR 0.91, 95% CI 0.63 to 1.31; four trials, 912 women; GRADE: low-quality evidence) or large-for-gestational age (average RR 0.60, 95% CI 0.19 to 1.86; three trials, 777 babies; Tau² = 0.61; P = 0.07; I² = 62%; GRADE: very low-quality evidence) between the low-GI and moderate- to high-GI dietary advice groups. The trials did not report on: hypertensive disorders of pregnancy; perinatal mortality; neonatal mortality and morbidity.No clear differences were shown for caesarean birth (RR 1.27, 95% CI 0.79 to 2.04; two trials, 201 women; GRADE: very low-quality evidence) and gestational weight gain (MD -1.23 kg, 95% CI -4.08 to 1.61; four trials, 787 women; Tau² = 7.31; I² = 90%; GRADE: very low-quality evidence), or for other reported secondary outcomes.The trials did not report the majority of secondary outcomes including those related to long-term health and health service use and costs. We were not able to assess the following outcomes using GRADE: perineal trauma; postnatal depression; maternal type 2 diabetes; neonatal hypoglycaemia; childhood/adulthood adiposity; type 2 diabetes; and neurosensory disability. High-fibre dietary advice versus standard dietary advice (one trial) The one trial in this comparison reported on two secondary outcomes. No clear difference between the high-fibre and standard dietary advice groups observed for mean blood glucose (following an oral glucose tolerance test at 35 weeks), and birthweight.

AUTHORS' CONCLUSIONS

Very low-quality evidence from five trials suggests a possible reduction in GDM risk for women receiving dietary advice versus standard care, and low-quality evidence from four trials suggests no clear difference for women receiving low- versus moderate- to high-GI dietary advice. A possible reduction in pregnancy-induced hypertension for women receiving dietary advice was observed and no clear differences were seen for other reported primary outcomes. There were few outcome data for secondary outcomes.For outcomes assessed using GRADE, evidence was considered to be low to very low quality, with downgrading based on study limitations (risk of bias), imprecision, and inconsistency.More high-quality evidence is needed to determine the effects of dietary advice interventions in pregnancy. Future trials should be designed to monitor adherence, women's views and preferences, and powered to evaluate effects on short- and long-term outcomes; there is a need for such trials to collect and report on core outcomes for GDM research. We have identified five ongoing studies and four are awaiting classification. We will consider these in the next review update.

Pregnancy urinary phthalate metabolite concentrations and gestational diabetes risk factors

BACKGROUND

Epidemiologic studies suggest phthalate metabolite concentrations are associated with type 2 diabetes. GDM is a strong risk factor for type 2 diabetes. Little is known about phthalates and GDM risk factors (i.e. 1st trimester body mass index (BMI), gestational weight gain (GWG), and 2nd trimester glucose levels).

METHODS

A total of 350 women participating in Lifecodes pregnancy cohort (Boston, MA), delivered at term and had pregnancy urinary phthalate metabolite concentrations. Nine specific gravity-adjusted urinary phthalate metabolites were evaluated. General linear regression was used to assess associations between quartiles of phthalate metabolites and continuous 1st trimester BMI and late 2nd trimester blood glucose. Linear mixed models were used for total GWG. Multivariable logistic regression was used for phthalate concentrations and categorized GWG and impaired glucose tolerance defined as glucose≥140mg/dL based on a 50-gram glucose load test. Models were adjusted for potential confounders.

RESULTS

There were no associations between 1st trimester urinary phthalate metabolite concentrations and 1st trimester BMI. Mono-ethyl phthalate concentrations averaged across pregnancy were associated with a 2.17 increased odds of excessive GWG (95% CI: 0.98, 4.79). Second trimester mono-ethyl phthalate was associated with increased odds of impaired glucose tolerance (adj. OR: 7.18; 95% CI: 1.97, 26.15). A summary measure of di-2-ethylhexyl phthalate metabolite concentrations were inversely associated with impaired glucose tolerance (adj. OR: 0.25; adj. 95% CI: 0.08, 0.85).

CONCLUSIONS

Higher exposure to mono-ethyl phthalate, a metabolite of the parent compound of di-ethyl phthalate, may be associated with excessive GWG and impaired glucose tolerance; higher di-2-ethylhexyl phthalate was associated with reduced odds of impaired glucose tolerance.

Effects of probiotics (Vivomixx®) in obese pregnant women and their newborn: study protocol for a randomized controlled trial

Background

Maternal obesity is associated with increased risks of adverse pregnancy-related complications and outcomes for both mothers and infants. Overweight and obese women have an increased risk of pregnancy-induced hypertension, preeclampsia and gestational diabetes mellitus (GDM). Infant Body Mass index (BMI) and the risk of obesity in adulthood are related to maternal gestational weight gain (GWG). Preventive lifestyle and dietary interventions are time-consuming and do not always reduce GWG or the risk of maternal pregnancy complications. Recent research has indicated that the gut microbiota may play a significant role in the development of obesity. Some studies have indicated that the daily consumption of probiotics may reduce the risk of preeclampsia, maintain serum insulin levels and reduce the frequency of GDM in pregnant women. The aims of this study are to investigate whether daily probiotic supplements in obese women during pregnancy can limit gestational weight gain, improve glucose homeostasis and thereby improve maternal, fetal and infant health outcomes.

Methods

A pilot study including 50 obese pregnant nulliparous women with a prepregnancy BMI of between 30 and 35 kg/m² will be randomized to receive daily probiotics (four capsules of Vivomixx®; total of 450 billion CFU/day, including eight probiotic bacterial strains) or placebo from gestational age 14–20 weeks until delivery. The infants will be followed until 9 months of age. The women will be monitored by weight, blood, fecal, vaginal and urine samples, diet questionnaires and hospital record review. Primary outcomes are: maternal weight gain, glycated hemoglobin (HbA1c) level and changes in glucose concentration measured during an oral glucose tolerance test. Secondary outcomes are: microbiota and inflammatory markers in mother and child, pregnancy complications, pregnancy outcomes, physical activity and the body composition of the neonate.

Discussion

We expect to find alterations in the metabolic profiles, microbiota and possibly pregnancy outcomes. From a clinical point of view the effects of Vivomixx® could control weight gain and reduce complications during pregnancy by inducing changes in the gut microbiota. Furthermore, this intervention during pregnancy could influence the infant’s microbiota, which could have important implications for infant development and health.

Trial registration

ClincalTrials.gov Identifier: NCT02508844, registered on 11 May 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1617-5) contains supplementary material, which is available to authorized users.

The risk factors for gestational diabetes mellitus: A retrospective study

OBJECTIVE

To investigate the risk factors for developing GDM among Taiwanese pregnant women.

DESIGN

A retrospective cohort and case-control study.

SETTING

At a medical centre in Southern Taiwan.

PARTICIPANTS

The hospitalised pregnant women who were diagnosed with either GDM or normal glucose tolerance (NGT) between 1997 and 2011. The glucose tolerance test results were interpreted according to criteria established by the National Diabetes Data Group for GDM. Participants were divided into either a GDM group (case group) or a normal glucose tolerance (NGT) group (control group) in order to determine the risk factors for GDM.

MEASUREMENTS

With a retrospective chart review, data regarding demographics, a family history of diabetes, history of gestation, and physiological index for pre- and postpregnancy periods were collected. χ² tests and independent t tests were used to examine the correlations between demographic characteristics and GDM. Stepwise multivariate logistic regression was used to determine the factors associated with GDM.

FINDINGS

The results of the comparison between the GDM group (n=106) and the NGT group (n=406) showed that the risk factors for GDM were maternal age, education, a family history of diabetes, and prepregnancy body mass index (BMI).

KEY CONCLUSION AND IMPLICATION FOR PRACTICE

Older age, lower levels of education, a family history of diabetes, and higher prepregnancy BMI were significant risk factors for GDM. In addition to performing risk factor assessment, health care providers should proactively promote the importance of GDM screening to pregnant women at their first antenatal visit.

Simulation modelling as a tool for knowledge mobilisation in health policy settings: a case study protocol

BACKGROUND

Evidence-informed decision-making is essential to ensure that health programs and services are effective and offer value for money; however, barriers to the use of evidence persist. Emerging systems science approaches and advances in technology are providing new methods and tools to facilitate evidence-based decision-making. Simulation modelling offers a unique tool for synthesising and leveraging existing evidence, data and expert local knowledge to examine, in a robust, low risk and low cost way, the likely impact of alternative policy and service provision scenarios. This case study will evaluate participatory simulation modelling to inform the prevention and management of gestational diabetes mellitus (GDM). The risks associated with GDM are well recognised; however, debate remains regarding diagnostic thresholds and whether screening and treatment to reduce maternal glucose levels reduce the associated risks. A diagnosis of GDM may provide a leverage point for multidisciplinary lifestyle modification interventions. This research will apply and evaluate a simulation modelling approach to understand the complex interrelation of factors that drive GDM rates, test options for screening and interventions, and optimise the use of evidence to inform policy and program decision-making.

METHODS/DESIGN

The study design will use mixed methods to achieve the objectives. Policy, clinical practice and research experts will work collaboratively to develop, test and validate a simulation model of GDM in the Australian Capital Territory (ACT). The model will be applied to support evidence-informed policy dialogues with diverse stakeholders for the management of GDM in the ACT. Qualitative methods will be used to evaluate simulation modelling as an evidence synthesis tool to support evidence-based decision-making. Interviews and analysis of workshop recordings will focus on the participants' engagement in the modelling process; perceived value of the participatory process, perceived commitment, influence and confidence of stakeholders in implementing policy and program decisions identified in the modelling process; and the impact of the process in terms of policy and program change.

DISCUSSION

The study will generate empirical evidence on the feasibility and potential value of simulation modelling to support knowledge mobilisation and consensus building in health settings.

Exposure to organophosphorus and organochlorine pesticides, perfluoroalkyl substances, and polychlorinated biphenyls in pregnancy and the association with impaired glucose tolerance and gestational diabetes mellitus: The MIREC Study

BACKGROUND

Studies report increases in rates of gestational diabetes mellitus (GDM) over recent decades. Environmental chemicals may increase the risk of diabetes through impacts on glucose metabolism, mitochondrial dysfunction, and endocrine-disrupting mechanisms including effects on pancreatic β-cell function and adiponectin release.

OBJECTIVES

To determine the associations between pesticides, perfluoroalkyl substances (PFASs) and polychlorinated biphenyls (PCBs) measured in early pregnancy and impaired glucose tolerance (IGT) and GDM in a Canadian birth cohort.

METHODS

Women enrolled in the Maternal-Infant Research on Environmental Chemicals (MIREC) Study were included if they had a singleton delivery and did not have pre-existing diabetes. Exposure variables included three organophosphorus (OP) pesticide metabolites detected in first-trimester urine samples, as well as three organochlorine (OC) pesticides, three PFASs, and four PCBs in first-trimester blood samples. Gestational IGT and GDM were assessed by chart review in accordance with published guidelines. Adjusted logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CI) for the association between quartiles of environmental chemicals and both gestational IGT and GDM.

RESULTS

Of the 2001 women recruited into the MIREC cohort, 1274 met the inclusion criteria and had outcome and biomonitoring data available. Significantly lower odds of GDM were observed in the third and fourth quartiles of dimethylphosphate (DMP) and in the fourth quartile of dimethylthiophosphate (DMTP) in adjusted analyses (DMP Q3: OR=0.2, 95% CI=0.1-0.7; DMP Q4: OR=0.3, 95% CI=0.1-0.8; DMTP: OR=0.3, 95% CI=0.1-0.9). Significantly elevated odds of gestational IGT was observed in the second quartile of perfluorohexane sulfonate (PFHxS) (OR=3.5, 95% CI=1.4-8.9). No evidence of associations with GDM or IGT during pregnancy was observed for PCBs or OC pesticides.

CONCLUSIONS

We did not find consistent evidence for any positive associations between the chemicals we examined and GDM or IGT during pregnancy. We observed statistical evidence of inverse relationships between urine concentrations of DMP and DMTP with GDM. We cannot rule out the influence of residual confounding due to unmeasured protective factors, such as nutritional benefits from fruit and vegetable consumption, also associated with pesticide exposure, on the observed inverse associations between maternal OP pesticide metabolites and GDM. These findings require further investigation.

Risks associated with obesity in pregnancy, for the mother and baby: a systematic review of reviews

Maternal obesity is linked with adverse outcomes for mothers and babies. To get an overview of risks related to obesity in pregnant women, a systematic review of reviews was conducted. For inclusion, reviews had to compare pregnant women of healthy weight with women with obesity, and measure a health outcome for mother and/or baby. Authors conducted full-text screening, quality assurance using the AMSTAR tool and data extraction steps in pairs. Narrative analysis of the 22 reviews included show gestational diabetes, pre-eclampsia, gestational hypertension, depression, instrumental and caesarean birth, and surgical site infection to be more likely to occur in pregnant women with obesity compared with women with a healthy weight. Maternal obesity is also linked to greater risk of preterm birth, large-for-gestational-age babies, foetal defects, congenital anomalies and perinatal death. Furthermore, breastfeeding initiation rates are lower and there is greater risk of early breastfeeding cessation in women with obesity compared with healthy weight women. These adverse outcomes may result in longer duration of hospital stay, with concomitant resource implications. It is crucial to reduce the burden of adverse maternal and foetal/child outcomes caused by maternal obesity. Women with obesity need support to lose weight before they conceive, and to minimize their weight gain in pregnancy.

Diet and exercise interventions for preventing gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with a wide range of adverse health consequences for women and their babies in the short and long term. With an increasing prevalence of GDM worldwide, there is an urgent need to assess strategies for GDM prevention, such as combined diet and exercise interventions.

OBJECTIVES

To assess the effects of combined diet and exercise interventions for preventing GDM and associated adverse health consequences for women and their babies.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (11 February 2014) and reference lists of retrieved studies. We updated the search in February 2015 but these results have not yet been incorporated and are awaiting classification.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and cluster-RCTs assessing the effects of interventions that included diet and exercise components. We included studies where combined diet and exercise interventions were compared with no intervention (i.e. standard care).We planned to also compare diet and exercise interventions with alternative diet and/or exercise interventions but no trials were identified for this comparison.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of the included studies. Data were checked for accuracy.

MAIN RESULTS

We included 13 randomised controlled trials (involving 4983 women and their babies). We assessed the included trials as being of moderate risk of bias overall.When comparing women receiving a diet and exercise intervention with those receiving no intervention, there was no clear difference in the risk of developing GDM (average risk ratio (RR) 0.92, 95% confidence interval (CI) 0.68 to 1.23; 11 trials, 3744 women), caesarean section (RR 0.92, 95% CI 0.83 to 1.01; seven trials, 3246 women), or large-for-gestational age (RR 0.90, 95% CI 0.77 to 1.05; 2950 infants). Only one trial reported on perinatal mortality, and found no clear difference in the risk of stillbirth (RR 0.99, 95% CI 0.29 to 3.42; 2202 fetuses) or neonatal death (RR 0.99, 95% CI 0.06 to 15.85; 2202 neonates).Very few differences were shown between groups for the review's secondary outcomes, including for induction of labour, perineal trauma, pre-eclampsia, postpartum haemorrhage and infection, macrosomia, birthweight, small-for-gestational age, ponderal index, neonatal hypoglycaemia requiring treatment, hyperbilirubinaemia requiring treatment, shoulder dystocia, bone fracture or nerve palsy. Women receiving a combined diet and exercise intervention were, however, found to have a reduced risk of preterm birth compared with women receiving no intervention (RR 0.71, 95% CI 0.55 to 0.93; five trials, 2713 women).A trend towards reduced weight gain during pregnancy was shown for women receiving the combined diet and exercise intervention (mean difference (MD) -0.76 kg, 95% CI -1.55 to 0.03; eight trials, 2707 women; P = 0.06, random-effects); but no clear difference in postnatal weight retention was observed overall.In relation to adherence to the interventions, a number of trials that reported on behaviour modifications showed benefits in diet- (5/8 trials) and physical activity- (4/8 trials) related behaviours for women receiving the combined diet and exercise intervention, compared with women receiving no intervention; however there was notable variation across trials in outcomes measured and results observed. Only two trials reported on well-being and quality of life of women, and did not observe differences between groups for these outcomes.Very few trials reported on outcomes relating to the use of health services, although one trial suggested a reduced length of antenatal hospital stay for women receiving a combined diet and exercise intervention (MD -0.27 days, 95% CI -0.49 to -0.05; 2153 women).No information was available on outcomes for the infant as a child or adult, or for most longer-term outcomes for the mother.

AUTHORS' CONCLUSIONS

There are limitations associated with the available RCT evidence on the effects of combined diet and exercise interventions during pregnancy for preventing GDM. Results from 13 RCTs (of moderate quality) suggest no clear difference in the risk of developing GDM for women receiving a combined diet and exercise intervention compared with women receiving no intervention. However, the ability to draw firm conclusions was limited by variations in the quality of trials, characteristics of the interventions and populations assessed, and outcome definitions between trials.Based on the data currently available, conclusive evidence is not available to guide practice. Further large, well-designed RCTs, addressing the limitations of previous studies, are needed to assess the effects of combined interventions on preventing GDM and other relevant pregnancy outcomes including caesarean birth, large-for-gestational age and perinatal mortality. Health service utilisation and costs, and longer-term outcomes for mothers and their babies should be included. We identified another 16 trials which are ongoing and we will consider these for inclusion in the next update of this review.

The first trimester: prediction and prevention of the great obstetrical syndromes

A number of groups are currently examining the potential of screening for pre-eclampsia and gestational diabetes at 12 weeks' gestation. This can be performed at the time of combined first-trimester screening for aneuploidy using a similar method of regression analysis to combine multiple demographic and investigative factors. At present, research into the prediction of pre-eclampsia is more robust and is associated with the potential for therapeutic intervention that can reduce the prevalence of early-onset pre-eclampsia and improve maternal and neonatal outcomes.

A mixed-methods study on factors influencing prenatal weight gain in ethnic-minority women

INTRODUCTION

Gaining too much weight in pregnancy is associated with perinatal complications and increases the risks of future obesity for both women and their infants. Unfortunately, women enrolled in intervention trials have seen little improvement in adherence to prenatal weight gain recommendations compared to women receiving standard prenatal care. Therefore, the purpose of this descriptive mixed-methods study was to explore factors related to excessive weight gain in pregnancy.

METHODS

Nonpregnant nulliparous women, currently pregnant women, and postpartum women (N = 43) were recruited from a health center serving an inner-city minority community. Women completed questionnaires on knowledge, self-efficacy, and behaviors related to nutrition, exercise, and prenatal weight gain. Fifteen of these women participated in focus groups. Focus group data were analyzed using ATLAS.ti (Scientific Software Development GmbH, Berlin, Germany). Codes were created, themes were identified, and consensus was reached through multiple iterations of the analysis by study personnel.

RESULTS

Excessive weight gain was common. Nutritional knowledge was poor and significantly lower among nonpregnant nulliparous women. Women felt sure that they could engage in healthy behaviors, but few did so. Participants in focus groups identified multiple barriers to healthy behaviors in pregnancy and made suggestions on how to help women more readily make improvements in these behaviors.

DISCUSSION

Strategies identified in this study such as providing focused education directed at nonpregnant nulliparous women, stressing portion control, helping women better manage their cravings, and providing more pragmatic support and resources need to be explored in future research.

Gestational diabetes mellitus among Nordic Caucasian women: prevalence and risk factors according to WHO and simplified IADPSG criteria

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with both maternal and offspring adverse effects. The World Health Organization (WHO) has recently adopted novel GDM criteria. The aim of this study was to evaluate the former WHO and a simplified version of the new International Association for Diabetes in Pregnancy Study Group (IADPSG) criteria as to prevalence of and risk factors for GDM in a Nordic Caucasian population.

METHODS

A 75 g oral glucose tolerance test was performed in 687 women at 18-22 and 32-36 pregnancy weeks. GDM was defined according to the WHO criteria as fasting plasma glucose ≥ 7.0 mmol/L and/or 2-hour plasma glucose ≥ 7.8 mmol/L and by a simplified version of the IADPSG criteria as either fasting glucose ≥ 5.1 mmol/L and/or 2-h plasma glucose ≥ 8.5 mmol/L. One-hour glucose values were not available and were thus not included in the diagnosis of GDM by IADPSG. Prevalence of GDM during pregnancy and risk factors for GDM at 18-22 weeks were studied in retrospect according to each of the two criteria.

RESULTS

The total prevalence of GDM during pregnancy was 6.1% (42/687) for the WHO criteria and 7.4% (51/687) for the simplified IADPSG criteria. High maternal age and short stature were independently associated with WHO GDM. Maternal age, fasting insulin and no regular exercise at 18-22 pregnancy weeks associated with simplified IADPSG GDM.

CONCLUSIONS

Simplified IADPSG criteria moderately increase GDM prevalence compared with the WHO criteria. Risk factors for GDM differ with the diagnostic criteria used.

Dietary Intakes in the Nutritional Management Of Gestational Diabetes Mellitus

Purpose: Changes were examined in energy intakes and percentage of energy from macronutrients in response to nutritional intervention in women with gestational diabetes mellitus (GDM).

Methods: The study included 17 women with GDM and 27 women with normal glucose tolerance (controls). Women with GDM were followed by a multidisciplinary team; they received dietary counselling by a registered dietitian, and were prescribed diets with 40% to 45% energy from carbohydrate (CHO), 20% to 25% from protein, and 30% to 35% from fat. Dietary intakes were assessed with food frequency questionnaires before the intervention (26.9 ± 3.8 weeks) and after the intervention (32.6 ± 0.6 weeks).

Results: After the intervention, women with GDM reduced their total energy intake to reach lower values than did controls (P value for time-group interaction ≤0.05). A concomitant reduction in total CHO and glucose intakes in women with GDM led to significantly lower values compared with intakes in controls (P values for time-group interaction ≤0.001 for all). The post-intervention rate of weight gain in women with GDM was within the Institute of Medicine (IOM)-recommended values, while the post-intervention rate of weight gain in controls was above IOM-recommended values (0.30 ± 0.27 versus 0.61 ± 0.50 kg/week, P≤0.05).

Conclusions: These results suggest that this multidisciplinary medical and nutritional intervention was effective in the achievement of prescribed macronutrient distribution and controlling gestational weight gain in Canadian women with GDM.