Recurrent gestational diabetes: risk factors, diagnosis, management, and implications

Maternal Weight and Gestational Diabetes Impacts on Child Health: A Narrative Review

Maternal weight and gestational diabetes mellitus (GDM) have significant implications for both maternal and child health. This narrative review explores the intricate relationship between maternal pre-pregnancy weight, gestational weight gain, and GDM, focusing on their short- and long-term effects on child health outcomes. The review highlights evidence linking maternal obesity and GDM to increased risks of adverse outcomes in infants and children, such as macrosomia, neonatal hypoglycemia, childhood obesity, and metabolic disorders. It also discusses the intergenerational transmission of metabolic risk, underscoring the importance of early intervention and prevention strategies in maternal healthcare. Furthermore, the review emphasizes the need for tailored approaches to managing maternal weight and GDM to mitigate potential risks and improve health outcomes for future generations. Key recommendations include promoting healthy preconception weight, monitoring gestational weight gain, and enhancing postnatal follow-up for both mothers and children. This review underscores the critical role of maternal health in shaping the developmental trajectory of offspring and highlights opportunities for healthcare professionals to reduce the long-term impact of GDM on child health.

Predicting recurrent gestational diabetes mellitus using artificial intelligence models: a retrospective cohort study

BACKGROUND

We aimed to develop novel artificial intelligence (AI) models based on early pregnancy features to forecast the likelihood of recurrent gestational diabetes mellitus (GDM) before 14 weeks of gestation in subsequent pregnancies.

METHODS

This study involved a cohort of 588 women who had two consecutive singleton deliveries and were diagnosed with GDM during the index pregnancy. The least absolute shrinkage and selection operator (LASSO) regression analysis were used for feature selection. 5 AI algorithms, namely support vector machine (SVM), extreme gradient boosting (XGB), light gradient boosting (LGB), decision tree classifier (DTC), and random forest (RF) classifier, and traditional multivariate logistic regression (LR) model, were employed to construct predictive models for recurrent GDM.

RESULTS

326 (55.4%) experienced GDM recurrence in subsequent pregnancy. In the training set (67% of the study sample), 13 features were selected for AI models construction. In the testing set (33% of the study sample), the AI models (LGB, RF, and XGB) exhibited outstanding discrimination, with AUROC values of 0.942, 0.936, and 0.924, respectively. The traditional LR model showed moderate discrimination (AUROC = 0.696). LGB, RF, and XGB models also demonstrated excellent calibration, while other models indicated a lack of fit. All AI models showed superior overall net benefits, with LGB, RF, and XGB outperforming the others.

CONCLUSIONS

The proposed LGB model demonstrated exceptional accuracy, excellent calibration, and superior overall net benefits. These advancements have the potential to assist healthcare professionals in advising women with a history of GDM and in developing preventive strategies to mitigate the adverse effects on maternal and fetal well-being.

Prenatal exposure to polycyclic aromatic hydrocarbons and phthalate acid esters and gestational diabetes mellitus: A prospective cohort study

BACKGROUND

Polycyclic aromatic hydrocarbons and phthalate acid esters (PAHs & PAEs), known as endocrine disrupting chemicals (EDCs), widely exist in daily life and industrial production. Previous studies have suggested that PAHs & PAEs may modify the intrauterine homeostasis and have adverse effects on fetal development. However, epidemiological evidence on the associations between PAHs & PAEs and gestational diabetes mellitus (GDM) is still limited.

OBJECTIVE

To investigate the effects of prenatal PAHs &PAEs exposure on the risk of GDM and hyperglycemia in pregnant women.

METHODS

The study population was a total of 725 pregnant women from a prospective birth cohort study conducted from December 2019 to December 2021. Blood glucose levels were collected by the hospital information system. Urinary PAHs & PAEs concentrations were determined by gas chromatography tandem mass spectrometry. The Poisson regression in a generalized linear model (GLM), multiple linear regression, quantile-based g-computation method (qgcomp), and Bayesian kernel machine regression (BKMR) were applied to explore and verify the individual and overall effects of PAHs & PAEs on glucose homeostasis. Potential confounders were adjusted in all statistical models.

RESULTS

A total of 179 (24.69%) women were diagnosed with GDM. The Poisson regression suggested that a ln-unit increment of 4-OHPHE (4-hydroxyphenanthrene) (adjusted Risk Ratio (aRR) = 1.13; 1.02-1.26) was associated with the increased GDM risk. Mixed-exposure models showed similar results. We additionally found that MBZP (mono-benzyl phthalate) (aRR = 1.19; 1.02-1.39) was positively related to GDM risk in qgcomp model. Although neither model demonstrated that 2-OHNAP (2-hydroxynaphthalene) and 9-OHFLU (9-hydroxyfluorene) increased the risk of GDM, 2-OHNAP and 9-OHFLU exposure significantly increased blood glucose levels. BKMR model further confirmed that overall effects of PAHs & PAEs were significantly associated with the gestational hyperglycemia and GDM risk.

CONCLUSIONS

Our study presents that environmental exposure to PAHs & PAEs was positively associated with gestational glucose levels and the risks of developing GDM. In particular, 2-OHNAP, 9-OHFLU, 4-OHPHE and MBZP may serve as important surveillance markers to prevent the development of GDM.

Development of a risk prediction model for postpartum onset of type 2 diabetes mellitus, following gestational diabetes; the lifestyle InterVention in gestational diabetes (LIVING) study

AIMS

This study aimed to develop a prediction model for identifying a woman with gestational diabetes mellitus (GDM) at high risk of type 2 diabetes (T2DM) post-birth.

METHODS

Utilising data from 1299 women in the Lifestyle Intervention IN Gestational Diabetes (LIVING) study, two models were developed: one for pregnancy and another for postpartum. Key predictors included glucose test results, medical history, and biometric indicators.

RESULTS

Of the initial cohort, 124 women developed T2DM within three years. The study identified seven predictors for the antenatal T2DM risk prediction model and four for the postnatal one. The models demonstrated good to excellent predictive ability, with Area under the ROC Curve (AUC) values of 0.76 (95% CI: 0.72 to 0.80) and 0.85 (95% CI: 0.81 to 0.88) for the antenatal and postnatal models, respectively. Both models underwent rigorous validation, showing minimal optimism in predictive capability. Antenatal model, considering the Youden index optimal cut-off point of 0.096, sensitivity, specificity, and accuracy were measured as 70.97%, 70.81%, and 70.82%, respectively. For the postnatal model, considering the cut-off point 0.086, sensitivity, specificity, and accuracy were measured as 81.40%, 75.60%, and 76.10%, respectively.

CONCLUSIONS

These models are effective for predicting T2DM risk in women with GDM, although external validation is recommended before widespread application.

Recurrence Risk of Pregnancy Complications in Twin and Singleton Deliveries

OBJECTIVE

 This study aimed to estimate and compare the recurrence risk of preterm birth (PTB), gestational diabetes mellitus (GDM), gestational hypertension (GH), and preeclampsia and eclampsia (PE and E) in subsequent pregnancy groups (index-subsequent) of singleton-singleton (n = 49,868), twin-singleton (n = 448), and singleton-twin (n = 723) pregnancies.

STUDY DESIGN

 Birthing individuals from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Consecutive Pregnancy Study (2002-2010) with ≥ 2 singleton or twin deliveries were examined. Adjusted relative risks (aRR) and 95% confidence intervals (CI) for recurrent PTB, GDM, GH, and PE and E were estimated using Poisson regression models with robust variance estimators.

RESULTS

 The aRR of PTB and GDM ranged from 1.4 to 5.1 and 5.2 to 22.7, respectively, with the greatest recurrence relative risk for both conditions in singleton-singleton subsequent pregnancies (PTB: aRR = 5.1 [95% CI: 4.8-5.5], GDM: aRR = 22.7 [95% CI: 20.8-24.8]). The aRR of GH and PE and E ranged from 2.8 to 7.6 and 3.2 to 9.2, respectively, with the greatest recurrence relative risk for both conditions in twin-singleton subsequent pregnancies (GH: aRR = 7.6 [95% CI: 2.8-20.5], PE and E: aRR = 9.2 [95% CI: 2.9-28.6]).

CONCLUSION

 Recurrence relative risk was increased for PTB, GDM, GH, and PE and E in all subsequent pregnancy groups, which varied in magnitude based on the birth number of the index and subsequent pregnancy. This information provides insight into risk management for subsequent pregnancies including multiples.

KEY POINTS

· Recurrence risk for all conditions is persistent in all subsequent pregnancy groups.. · The magnitude of risk varies by the presence of multiples in the index or subsequent pregnancy.. · Singleton-singleton pregnancies are at the greatest risk of PTB.. · Singleton-singleton pregnancies are at the greatest risk of GDM.. · Twin-singleton pregnancies are at the greatest risk of hypertensive disorders..

Different intensities of glycaemic control for women with gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) has major short- and long-term implications for both the mother and her baby. GDM is defined as a carbohydrate intolerance resulting in hyperglycaemia or any degree of glucose intolerance with onset or first recognition during pregnancy from 24 weeks' gestation onwards and which resolves following the birth of the baby. Rates for GDM can be as high as 25% depending on the population and diagnostic criteria used, and overall rates are increasing globally. There is wide variation internationally in glycaemic treatment target recommendations for women with GDM that are based on consensus rather than high-quality trials.

OBJECTIVES

To assess the effect of different intensities of glycaemic control in pregnant women with GDM on maternal and infant health outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (26 September 2022), and reference lists of the retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), cluster-RCTs, and quasi-RCTs. Trials were eligible for inclusion if women were diagnosed with GDM during pregnancy and the trial compared tighter and less-tight glycaemic targets during management. We defined tighter glycaemic targets as lower numerical glycaemic concentrations, and less-tight glycaemic targets as higher numerical glycaemic concentrations.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods for carrying out data collection, assessing risk of bias, and analysing results. Two review authors independently assessed trial eligibility for inclusion, evaluated risk of bias, and extracted data for the four included studies. We assessed the certainty of evidence for selected outcomes using the GRADE approach. Primary maternal outcomes included hypertensive disorders of pregnancy and subsequent development of type 2 diabetes. Primary infant outcomes included perinatal mortality, large-for-gestational-age, composite of mortality or serious morbidity, and neurosensory disability.

MAIN RESULTS

This was an update of a previous review completed in 2016. We included four RCTs (reporting on 1731 women) that compared a tighter glycaemic control with less-tight glycaemic control in women diagnosed with GDM. Three studies were parallel RCTs, and one study was a stepped-wedged cluster-RCT. The trials took place in Canada, New Zealand, Russia, and the USA. We judged the overall risk of bias to be unclear. Two trials were only published in abstract form. Tight glycaemic targets used in the trials ranged between ≤ 5.0 and 5.1 mmol/L for fasting plasma glucose and ≤ 6.7 and 7.4 mmol/L postprandial. Less-tight targets for glycaemic control used in the included trials ranged between < 5.3 and 5.8 mmol/L for fasting plasma glucose and < 7.8 and 8.0 mmol/L postprandial. For the maternal outcomes, compared with less-tight glycaemic control, the evidence suggests a possible increase in hypertensive disorders of pregnancy with tighter glycaemic control (risk ratio (RR) 1.16, 95% confidence interval (CI) 0.80 to 1.69, 2 trials, 1491 women; low certainty evidence); however, the 95% CI is compatible with a wide range of effects that encompass both benefit and harm. Tighter glycaemic control likely results in little to no difference in caesarean section rates (RR 0.98, 95% CI 0.82 to 1.17, 3 studies, 1662 women; moderate certainty evidence) or induction of labour rates (RR 0.96, 95% CI 0.78 to 1.18, 1 study, 1096 women; moderate certainty evidence) compared with less-tight control. No data were reported for the outcomes of subsequent development of type 2 diabetes, perineal trauma, return to pre-pregnancy weight, and postnatal depression. For the infant outcomes, it was difficult to determine if there was a difference in perinatal mortality (RR not estimable, 2 studies, 1499 infants; low certainty evidence), and there was likely no difference in being large-for-gestational-age (RR 0.96, 95% CI 0.72 to 1.29, 3 studies, 1556 infants; moderate certainty evidence). The evidence suggests a possible reduction in the composite of mortality or serious morbidity with tighter glycaemic control (RR 0.84, 95% CI 0.55 to 1.29, 3 trials, 1559 infants; low certainty evidence); however, the 95% CI is compatible with a wide range of effects that encompass both benefit and harm. There is probably little difference between groups in infant hypoglycaemia (RR 0.92, 95% CI 0.72 to 1.18, 3 studies, 1556 infants; moderate certainty evidence). Tighter glycaemic control may not reduce adiposity in infants of women with GDM compared with less-tight control (mean difference -0.62%, 95% CI -3.23 to 1.99, 1 study, 60 infants; low certainty evidence), but the wide CI suggests significant uncertainty. We found no data for the long-term outcomes of diabetes or neurosensory disability. Women assigned to tighter glycaemic control experienced an increase in the use of pharmacological therapy compared with women assigned to less-tight glycaemic control (RR 1.37, 95% CI 1.17 to 1.59, 4 trials, 1718 women). Tighter glycaemic control reducedadherence with treatment compared with less-tight glycaemic control (RR 0.41, 95% CI 0.32 to 0.51, 1 trial, 395 women). Overall the certainty of evidence assessed using GRADE ranged from low to moderate, downgraded primarily due to risk of bias and imprecision.

AUTHORS' CONCLUSIONS

This review is based on four trials (1731 women) with an overall unclear risk of bias. The trials provided data on most primary outcomes and suggest that tighter glycaemic control may increase the risk of hypertensive disorders of pregnancy. The risk of birth of a large-for-gestational-age infant and perinatal mortality may be similar between groups, and tighter glycaemic targets may result in a possible reduction in composite of death or severe infant morbidity. However, the CIs for these outcomes are wide, suggesting both benefit and harm. There remains limited evidence regarding the benefit of different glycaemic targets for women with GDM to minimise adverse effects on maternal and infant health. Glycaemic target recommendations from international professional organisations vary widely and are currently reliant on consensus given the lack of high-certainty evidence. Further high-quality trials are needed, and these should assess both short- and long-term health outcomes for women and their babies; include women's experiences; and assess health services costs in order to confirm the current findings. Two trials are ongoing.

Prediction of recurrent gestational diabetes mellitus: a retrospective cohort study

BACKGROUND

Women after gestational diabetes mellitus (GDM) are at increased risk for development of GDM recurrence. It was the aim of our study to evaluate factors for prediction of risk of recurrence.

METHODS

In this retrospective cohort study we included 159 women with GDM and a subsequent pregnancy. Putative risk factors for GDM recurrence were analyzed by logistic regression models. Results were compared to a cohort of age-matched women without GDM as controls (n = 318).

RESULTS

The overall risk of GDM recurrence was 72.3% (115/159). Risk factors of recurrence were a body mass index (BMI) ≥ 30 kg/m2 before the index pregnancy (odds ratio (OR) 2.8 [95% CI 1.3-6.2], p = 0,008), a BMI ≥ 25 kg/m2 before the subsequent pregnancy (OR 2.7 [95% CI 1.3-5.8]. p = 0.008), a positive family history (OR 4.3 [95% CI 1.2-15.4], p = 0.016) and insulin treatment during the index pregnancy (OR 2.3 [95% CI 1.1-4.6], p = 0.023). Delivery by caesarean section (index pregnancy) was of borderline significance (OR 2.2 [95% CI 0.9-5.2], p = 0.069). Interpregnancy weight gain, excessive weight gain during the index pregnancy and fetal outcome where not predictive for GDM recurrence. Neonates after GDM revealed a higher frequency of transfer to intensive care unit compared to healthy controls (OR 2.3 [95% CI 1.1-4.6], p = 0.0225). The best combined risk model for prediction of GDM recurrence including positive family history and a BMI ≥ 25 kg/m2 before the subsequent pregnancy revealed moderate test characteristics (positive likelihood ratio 7.8 [95% CI 1.1-54.7] and negative likelihood ratio 0.7 [95% CI 0.6-0.9]) with a positive predictive value of 96.6% in our cohort.

CONCLUSIONS

A positive family history of diabetes mellitus in combination with overweight or obesity were strongly associated with recurrence of a GDM in the subsequent pregnancy. Normalization of the pregravid BMI should be an effective approach for reducing the risk of GDM recurrence.

Glucose Testing in an Index Pregnancy and Outcomes in a Subsequent Pregnancy: Implications for Screening and a Novel Risk Calculator

OBJECTIVE

Our objective was to assess whether variables from an index pregnancy (PG1) can be used to guide testing for gestational diabetes mellitus (GDM) in a subsequent pregnancy (PG2) and to create a risk calculator for GDM in PG2.

STUDY DESIGN

This was a retrospective cohort study of patients delivering ≥2 singleton gestations at >24 weeks' gestation from June 2009 to December 2018, for whom results of a 1-hour glucose challenge test (GCT) were available from PG1. Univariable and multivariable analyses were performed to evaluate factors associated with GDM in PG2.

RESULTS

In total, 4,278 patients met the inclusion criteria. Among patients with a normal 1-hour GCT (<140 mg/dL) in PG1 (n = 3,719), 3.9% were diagnosed with GDM in PG2. In multivariable analysis of this group, GDM in PG2 was associated with higher GCT in PG1 (adjusted odds ratio [aOR]: 1.05, 95% confidence interval [CI]: 1.04-1.06), large for gestational age neonate in PG1 (aOR: 1.97, 95% CI: 1.24-3.13), and higher BMI (aOR: 1.08, 95% CI: 1.05-1.11). A novel risk calculator for GDM in PG2 was developed based on these associations. Using a risk cut-off of 15%, the calculator had a positive predictive value of 26% and a negative predictive value of 97%, with 3.2% of patients identified as "at risk". Among patients with abnormal 1-hour GCT in PG1, 38.3% (n = 214/559) had an abnormal 1-hour GCT in PG2 and 34.5% (n = 74/214) of these patients received a diagnosis of GDM.

CONCLUSION

A normal 1-hour GCT in an PG1 is followed by GDM in a subsequent pregnancy in only 3.9% of cases. A novel calculator supports replacing universal screening with targeted testing in subsequent pregnancies in this population. Among patients with an abnormal 1-hour GCT in PG1, nearly 40% have an abnormal 1-hour GCT in a subsequent pregnancy. Direct diagnostic testing can be considered in such patients.

KEY POINTS

· Normal GCT in a first pregnancy is associated with normal GCT in subsequent pregnancy.. · A risk calculator can target diabetes testing in a subsequent pregnancy.. · Abnormal GCT in a first pregnancy is associated with abnormal GCT in subsequent pregnancy..

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.

Gestational Diabetes Sensitizes Mice to Future Metabolic Syndrome That Can Be Relieved by Activating CAR

Diabetes and related metabolic syndrome are common metabolic disorders. Gestational diabetes mellitus (GDM) is rather prevalent in the clinic. Although most GDM resolves after therapeutic intervention and/or after delivery, the long-term health effect of GDM remains to be better understood. The constitutive androstane receptor (CAR), initially characterized as a xenobiotic receptor, was more recently proposed to be a therapeutic target for obesity and type 2 diabetes mellitus (T2DM). In this study, high-fat diet (HFD) feeding was used to induce GDM. Upon delivery, GDM mice were returned to chow diet until the metabolic parameters were normalized. Parous non-GDM control females or metabolically normalized GDM females were then subjected to HFD feeding to induce nongestational obesity and T2DM. Our results showed that GDM sensitized mice to metabolic abnormalities induced by a second hit of HFD. Treatment with the CAR agonist 1,4-bis [2-(3,5 dichloropyridyloxy)] benzene efficiently attenuated GDM-sensitized and HFD-induced obesity and T2DM, including decreased body weight, improved insulin sensitivity, inhibition of hyperglycemia and hepatic steatosis, increased oxygen consumption, and decreased adipocyte hypertrophy. In conclusion, our results have established GDM as a key risk factor for the future development of metabolic disease. We also propose that CAR is a therapeutic target for the management of metabolic disease sensitized by GDM.

Gestational Diabetes Mellitus pregnancy by pregnancy: early, late and nonrecurrent GDM

AIMS

To assess the GDM recurrence rate in a cohort of pregnant women with prior GDM, to compare two consecutive pregnancies complicated by GDM, to compare women with nonrecurrent and recurrent GDM and to stratify the latter in women with early and late recurrent GDM.

METHODS

Retrospective study including 113 women with GDM in an index pregnancy (G1), at least a postindex pregnancy (G2) and normal glucose tolerance in between. The GDM recurrence rate was assessed, and maternal and neonatal outcomes and pancreatic beta cell function of the index pregnancy were compared with those of the postindex pregnancy (G1 vs. G2). Women with nonrecurrent GDM were compared with those with recurrent GDM.

RESULTS

The GDM recurrence rate was 83.2% and the minimum prevalence of early recurrent GDM was 43,4%. The pregravid BMI of women with recurrent GDM increased between the two pregnancies (27.3 ± 5.98 vs. 28.1 ± 6.19 kg/m², p < 0.05). Women with recurrent GDM had a higher prepregnancy BMI than those with nonrecurrent GDM either at the index (27.3 ± 5.98 vs. 23.1 ± 4.78 kg/m², p < 0.05) or the postindex pregnancy (27 ± 6vs.24 ± 4,4 kg/m², p < 0.05).

CONCLUSIONS

GDM shows a high recurrence rate in our cohort of slightly overweight women, with an early GDM minimum prevalence of 43.4%.

Risk of gestational diabetes recurrence and the development of type 2 diabetes among women with a history of gestational diabetes and risk factors: a study among 18 clinical centers in China

BACKGROUND

Gestational diabetes mellitus (GDM) brings health issues for both mothers and offspring, and GDM prevention is as important as GDM management. It was shown that a history of GDM was significantly associated with a higher maternal risk for GDM recurrence. The incidence of GDM recurrence was unclear because of the incidence of second-child was low before 2016 in China. We aim to investigate the prevalence of GDM recurrence and its associated high-risk factors which may be useful for the prediction of GDM recurrence in China.

METHODS

A retrospective study was conducted which enrolled participants who underwent regular prenatal examination and delivered twice in the same hospital of 18 research centers. All participants were enrolled from January 2018 to October 2018, where they delivered the second baby during this period. A total of 6204 women were enrolled in this study, and 1002 women with a history of GDM were analyzed further. All participants enrolled in the study had an oral glucose tolerance test (OGTT) result at 24 to 28 weeks and were diagnosed as GDM in the first pregnancy according to the OGTT value (when any one of the following values is met or exceeded to the 75-g OGTT: 0 h [fasting], ≥5.10 mmol/L; 1 h, ≥10.00 mmol/L; and 2 h, ≥8.50 mmol/L). The prevalence of GDM recurrence and development of type 2 diabetes mellitus were calculated, and its related risk factors were analyzed.

RESULTS

In 6204 participants, there are 1002 women (1002/6204,16.15%) with a history of GDM and 5202 women (5202/6204, 83.85%) without a history of GDM. There are significant differences in age (32.43 ± 4.03 years vs. 33.00 ± 3.34 years vs. 32.19 ± 3.37 years, P  < 0.001), pregnancy interval (4.06 ± 1.44 years vs. 3.52 ± 1.43 years vs. 3.38 ± 1.35 years, P  = 0.004), prepregnancy body mass index (BMI) (27.40 ± 4.62 kg/m2vs. 23.50 ± 3.52 kg/m2vs. 22.55 ± 3.47 kg/m2, P < 0.001), history of delivered macrosomia (22.7% vs. 11.0% vs. 6.2%, P < 0.001) among the development of diabetes mellitus (DM), recurrence of GDM, and normal women. Moreover, it seems so important in the degree of abnormal glucose metabolism in the first pregnancy to the recurrence of GDM and the development of DM. There are significant differences in OGTT levels of the first pregnancy such as area under the curve of OGTT value (18.31 ± 1.90 mmol/L vs. 16.27 ± 1.93 mmol/L vs. 15.55 ± 1.92 mmol/L, P < 0.001), OGTT fasting value (5.43 ± 0.48 mmol/L vs. 5.16 ± 0.49 mmol/L vs. 5.02 ± 0.47 mmol/L, P < 0.001), OGTT 1-hour value (10.93 ± 1.34 mmol/L vs. 9.69 ± 1.53 mmol/L vs. 9.15 ± 1.58 mmol/L, P < 0.001), OGTT 2-hour value (9.30 ± 1.66 mmol/L vs. 8.01 ± 1.32 mmol/L vs. 7.79 ± 1.38 mmol/L, P < 0.001), incidence of impaired fasting glucose (IFG) (fasting plasma glucose ≥5.6 mmol/L) (31.3% vs. 14.6% vs. 8.8%, P < 0.001), and incidence of two or more abnormal OGTT values (68.8% vs. 39.7% vs. 23.9%, P < 0.001) among the three groups. Using multivariate analysis, the factors, such as age (1.07 [1.02-1.12], P = 0.006), prepregnancy BMI (1.07 [1.02, 1.12], P  = 0.003), and area under the curve of OGTT in the first pregnancy (1.14 [1.02, 1.26], P  = 0.02), have an effect on maternal GDM recurrence; the factors, such as age (1.28 [1.01-1.61], P  = 0.04), pre-pregnancy BMI (1.26 [1.04, 1.53], P = 0.02), and area under the curve of OGTT in the first pregnancy (1.65 [1.04, 2.62], P = 0.03), have an effect on maternal DM developed further.

CONCLUSIONS

The history of GDM was significantly associated with a higher maternal risk for GDM recurrence during follow-up after the first pregnancy. The associated risk factors for GDM recurrence or development of DM include age, high pre-pregnancy BMI, history of delivered macrosomia, the OGTT level in the first pregnancy, such as the high area under the curve of OGTT, IFG, and two or more abnormal OGTT values. To prevent GDM recurrence, women with a history of GDM should do the preconception counseling before preparing next pregnancy.

Recurrent gestational diabetes : Breaking the transgenerational cycle with lifestyle modification

PURPOSE

This literature review is aimed at examining the benefits of lifestyle modifications in preventing recurrent gestational diabetes (GDM). Worldwide GDM affects approximately 16.2% of all pregnancies with significant maternal, fetal and neonatal complications. Almost two thirds of pregnant women with GDM will develop type 2 diabetes mellitus (T2DM) in the years following pregnancy. The proportion of women affected by GDM is on the rise and reflects increasing trends in T2DM as well as adult and childhood obesity.

METHODS

Using predefined subject headings, we searched for relevant articles from the PubMed, Scopus, and Cochrane databases.

RESULTS

For high-risk women lifestyle modifications, such as dietary and exercise changes, are the mainstay of treatment to reduce negative outcomes for both women and their pregnancies. This includes reducing the incidence of recurrent GDM and future T2DM by intervening during pregnancy and in the postnatal period.

CONCLUSION

This review provides an overview of the literature to date, discusses different targeted approaches and how these interventions can optimise their benefits, and where further research is required.

Differing risk factors for new onset and recurrent gestational diabetes mellitus in multipara women: a cohort study

OBJECTIVES

To assess whether recurrent gestational diabetes mellitus (GDM) and newly diagnosed GDM share similar risk factors.

METHODS

The study recruited a cohort of 10,151 multipara women with singleton pregnancy who delivered between 2016 and 2019 in Beijing, China. The prevalence of recurrent GDM and associated risk factors were analyzed between women with and without prior GDM history.

RESULTS

Eight hundred and seventy-five (8.6%) multipara women had a diagnosis of GDM during previous pregnancies. The prevalence of GDM and pre-gestational diabetes mellitus were 48.34% (423/875) and 7.89% (69/875) if the women were diagnosed with GDM during previous pregnancies, as compared to 16.00% (1484/9276) and 0.50% (46/9276) if the women were never diagnosed with GDM before. In women without a history of GDM, a variety of factors including older maternal age, higher pre-pregnancy body mass index (PPBMI), prolonged interval between the two pregnancies, higher early pregnancy weight gain, family history of type 2 diabetes mellitus (T2DM), maternal low birth weight, and higher early pregnancy glycemic and lipid indexes were generally associated with an increased risk of GDM at subsequent pregnancy. In women with a history of GDM, higher PPBMI, higher fasting glucose level and maternal birthweight ≥4000 g were independent risk factors for recurrent GDM.

CONCLUSIONS

GDM reoccurred in nearly half of women with a history of GDM. Risk factors for recurrent GDM and newly diagnosed GDM were different. Identifying additional factors for GDM recurrence can help guide clinical management for future pregnancies to prevent GDM recurrence.

IDF Diabetes Atlas: Estimation of Global and Regional Gestational Diabetes Mellitus Prevalence for 2021 by International Association of Diabetes in Pregnancy Study Group's Criteria

AIMS

The approaches used to screen and diagnose gestational diabetes mellitus (GDM) vary widely. We generated a comparable estimate of the global and regional prevalence of GDM by International Association of Diabetes in Pregnancy Study Group (IADPSG)'s criteria.

METHODS

We searched PubMed and other databases and retrieved 57 studies to estimate the prevalence of GDM. Prevalence rate ratios of different diagnostic criteria, screening strategies and age groups, were used to standardize the prevalence of GDM in individual studies included in the analysis. Fixed effects meta-analysis was conducted to estimate standardized pooled prevalence of GDM by IDF regions and World Bank country income groups.

RESULTS

The pooled global standardized prevalence of GDM was 14.0% (95% confidence interval: 13.97-14.04%). The regional standardized prevalence of GDM were 7.1% (7.0-7.2%) in North America and Caribbean (NAC), 7.8% (7.2-8.4%) in Europe (EUR), 10.4% (10.1-10.7%) in South America and Central America (SACA), 14.2% (14.0-14.4%) in Africa (AFR), 14.7% (14.7-14.8%) in Western Pacific (WP), 20.8% (20.2-21.4%) in South-East Asia (SEA) and 27.6% (26.9-28.4%) in Middle East and North Africa (MENA). The standardized prevalence of GDM in low-, middle- and high-income countries were 12.7% (11.0-14.6%), 9.2% (9.0-9.3%) and 14.2% (14.1-14.2%), respectively.

CONCLUSIONS

The highest standardized prevalence of GDM was in MENA and SEA, followed by WP and AFR. Among the three World Bank country income groups, high income countries had the highest standardized prevalence of GDM. The standardized estimates for the prevalence of GDM provide an insight for the global picture of GDM.

The Influence of Practising Physical Activity on the Prevention and Treatment of Gestational Diabetes: A Systematic Review

BACKGROUND

During pregnancy, maintaining an inadequate lifestyle (bad eating habits, stress, consumption of toxic substances, etc.) generates complications such as pre-eclampsia, overweight, lumbar pain and Gestational Diabetes.

OBJECTIVE

This review was carried out with the objective to determine the influence of practising physical activity on the prevention and treatment of Gestational Diabetes; and to evaluate the efficacy of interventions based on therapeutic exercise in the management of such diseases.

METHOD

A systematic review of the publications of the last five years in Medline, Pubmed, Web of Science and Cinahl databases was conducting with the terms Exercise and Gestational Diabetes.

RESULTS

25 articles were found, 9 were observational studies that analysed physical activity habits through questionnaires, and other 16 applied an intervention. With respect to the frequency of the sessions, most of these studies applied their interventions three times per week, with all of them obtaining positive results. Regarding intensity, all the studies that referred to it concluded that it must be at least moderate, highlighting that, at all times, the limitations of pregnant women must be taken into account.

CONCLUSION

Both for the prevention and treatment of this disease, the physical activity must be performed for a minimum of three times per week, at least in moderate intensity, and must be based on aerobic, resistance and strength exercises.

First pregnancy risk factors and future gestational diabetes mellitus

PURPOSE

Gestational diabetes mellitus (GDM) affect about 17% of all pregnancies and is associated with significant short- and long-term health consequences for the mother and her offspring. Early diagnosis and prompt interventions may reduce these adverse outcomes. We aimed to identify first pregnancy characteristics as risk factors for GDM in subsequent pregnancy.

MATERIALS AND METHODS

A population-based nested case-control study was conducted in a large tertiary hospital. The study population included all women with two singleton consecutive pregnancies and deliveries, without GDM in the first pregnancy. Characteristics and complications of the first pregnancy were compared among cases and controls. A multivariable logistic regression model was used to study the association between pregnancy complications (in the first pregnancy) and GDM in the subsequent pregnancy, while adjusting for confounding variables.

RESULTS

A total of 38,750 women were included in the study, of them 1.9% (n = 728) had GDM in their second pregnancy. Mothers with GDM in their second pregnancy were more likely to have the following first pregnancy complications: hypertensive disorders, perinatal mortality, maternal obesity and fetal macrosomia. Results remained significant after adjustment for maternal age and inter-pregnancy interval. Having either one of the complications increased the risk for GDM by 2.33 (adjusted OR = 2.33; 95% CI 1.93-2.82) while a combination of two complications increased GDM risk by 5.38 (adjusted OR = 5.38; 95% CI 2.85-10.17).

CONCLUSIONS

First pregnancy without GDM complicated by hypertensive disorders, perinatal mortality, maternal obesity and fetal macrosomia was associated with an increased risk for GDM in the subsequent pregnancy. Women with these complications may benefit from early detection of GDM in their subsequent pregnancy.

Predictors of recurrent gestational diabetes mellitus: A Japanese multicenter cohort study and literature review

AIM

To clarify whether maternal characteristics or laboratory parameters could help predict the onset of recurrent gestational diabetes mellitus (GDM).

METHODS

We enrolled 615 women with consecutive singleton deliveries at or after 28 GW from two perinatal medical centers between 2011 and 2019 and divided them into four groups according to whether they had GDM in the first and second pregnancies. The outcome of this study was to clarify the incidence and the predictors of recurrent GDM.

RESULTS

We found that among 72 women (11.7%) who had GDM during their first pregnancy, the rate of recurrent GDM was 47.2%. The 34 women (5.5%) with recurrent GDM gained significantly less weight in the first and second pregnancies and lost less weight between the first delivery and the second conception compared with those women without GDM in both pregnancies. Of women with GDM during the first pregnancy, 21 scored 2 or 3 (multiple) positive points on a 75-g oral glucose tolerance test (OGTT) during their first pregnancies; the GDM recurrence rate among these women (66.7%) was significantly higher than that among the 51 women who scored 1 positive point (39.2%; p = 0.0411). During the first pregnancy, insulin administration therapy was significantly more frequent in women with recurrent GDM than in women without recurrent GDM (23.5% vs. 5.3%, p = 0.0396, respectively).

CONCLUSION

A predictor of recurrent GDM onset was a score of 2 or 3 positive points on the OGTT during the first pregnancy.

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.

Electronic Monitoring Of Mom's Schedule (eMOMS™): Protocol for a feasibility randomized controlled trial to improve postpartum weight, blood sugars, and breastfeeding among high BMI women

Background

Overweight and obesity are major risk factors for gestational diabetes among U.S. women. Evidence suggests that longer duration of breastfeeding among women with a history of gestational diabetes is associated with lower incidence of developing type 2 diabetes after pregnancy. Women may potentially benefit from a lifestyle change program that includes breastfeeding education and support.

Purpose

To describe the design and justification of a combined breastfeeding, national Diabetes Prevention Program (DPP)-based feasibility randomized controlled trial, the electronic Monitoring Of Mom's Schedule (eMOMS^TM) study. eMOMS^TM compares the feasibility and efficacy of three interventions on six-month postpartum weight loss among women with a BMI ≥25.

Methods

The intervention is delivered via Facebook and includes three groups: DPP and breastfeeding (eMOMS1); DPP only (eMOMS2); and Usual Care (eMOMS3). Recruitment is ongoing at two clinical sites (rural and urban). A total of 72 women, 24 per group, will be randomly assigned to one of the three groups. It is anticipated that women in eMOMS1 will have greater weight loss and increased length of breastfeeding at three and six months postpartum compared to women in eMOMS2 and eMOMS3. Additional data will be collected on metabolic markers, anthropometrics, physical activity, nutrition, breastfeeding, and depression. Program cost will be compared to that of traditionally scheduled group meetings. Expected study completion date: October 2021.

Conclusions

This study has the potential to define a high impact, cost effective intervention that can improve public health by reducing negative health outcomes associated with gestational diabetes among an at-risk population.

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).

Frequency and risk factors for recurrent gestational diabetes mellitus in primiparous women: a case control study

BACKGROUND

To investigate the frequency and risk factors for recurrent gestational diabetes mellitus (GDM) in Chinese primiparous women.

METHODS

Case control study. We investigated primiparous women who experienced GDM complications and had a subsequent pregnancy in the same hospital from January, 2012 to January, 2017. Ultimately, 78 women with recurrent GDM and 64 women with no recurrence were included. Clinical characteristics and biochemical parameters such as fasting plasma glucose (FPG), oral glucose tolerance test (OGTT) and lipid profiles were collected from medical records. We used an independent t-test and Chi-square test or Fisher's exact test to compare each variable. Univariate and multivariate logistic analyses were used to compute each odds ratio (OR) and 95% confidence interval (CI).

RESULTS

The frequency of recurrent GDM was 55%. We found postprandial 1-h glucose at the 75-g OGTT was positively related to GDM recurrence, whereas first-trimester FPG in first pregnancy was negatively related. The first-trimester HbA1c value was higher in the group with GDM recurrence than in the group with no recurrence, though the difference was not significant. Moreover, the group with GDM recurrence manifested significantly higher first-trimester triglyceride concentrations in subsequent pregnancies; the adjusted ORs (95% CI) were 1.43 (1.09-1.87), 0.24 (0.10-0.63), 3.59 (0.93-13.88) and 1.89 (1.13-3.16).

CONCLUSIONS

GDM recurred in more than half of subsequent pregnancies. Women with lower first-trimester FPG and higher postprandial 1-h glucose in first pregnancy, and with higher first-trimester triglyceride in subsequent pregnancy were at increased risk for GDM recurrence.

Treatments for women with gestational diabetes mellitus: an overview of Cochrane systematic reviews

BACKGROUND

Successful treatments for gestational diabetes mellitus (GDM) have the potential to improve health outcomes for women with GDM and their babies.

OBJECTIVES

To provide a comprehensive synthesis of evidence from Cochrane systematic reviews of the benefits and harms associated with interventions for treating GDM on women and their babies.

METHODS

We searched the Cochrane Database of Systematic Reviews (5 January 2018) for reviews of treatment/management for women with GDM. Reviews of pregnant women with pre-existing diabetes were excluded.Two overview authors independently assessed reviews for inclusion, quality (AMSTAR; ROBIS), quality of evidence (GRADE), and extracted data.

MAIN RESULTS

We included 14 reviews. Of these, 10 provided relevant high-quality and low-risk of bias data (AMSTAR and ROBIS) from 128 randomised controlled trials (RCTs), 27 comparisons, 17,984 women, 16,305 babies, and 1441 children. Evidence ranged from high- to very low-quality (GRADE). Only one effective intervention was found for treating women with GDM.EffectiveLifestyle versus usual careLifestyle intervention versus usual care probably reduces large-for-gestational age (risk ratio (RR) 0.60, 95% confidence interval (CI) 0.50 to 0.71; 6 RCTs, N = 2994; GRADE moderate-quality).PromisingNo evidence for any outcome for any comparison could be classified to this category.Ineffective or possibly harmful Lifestyle versus usual careLifestyle intervention versus usual care probably increases the risk of induction of labour (IOL) suggesting possible harm (average RR 1.20, 95% CI 0.99 to 1.46; 4 RCTs, N = 2699; GRADE moderate-quality).Exercise versus controlExercise intervention versus control for return to pre-pregnancy weight suggested ineffectiveness (body mass index, BMI) MD 0.11 kg/m², 95% CI -1.04 to 1.26; 3 RCTs, N = 254; GRADE moderate-quality).Insulin versus oral therapyInsulin intervention versus oral therapy probably increases the risk of IOL suggesting possible harm (RR 1.3, 95% CI 0.96 to 1.75; 3 RCTs, N = 348; GRADE moderate-quality).Probably ineffective or harmful interventionsInsulin versus oral therapyFor insulin compared to oral therapy there is probably an increased risk of the hypertensive disorders of pregnancy (RR 1.89, 95% CI 1.14 to 3.12; 4 RCTs, N = 1214; GRADE moderate-quality).InconclusiveLifestyle versus usual careThe evidence for childhood adiposity kg/m² (RR 0.91, 95% CI 0.75 to 1.11; 3 RCTs, N = 767; GRADE moderate-quality) and hypoglycaemia was inconclusive (average RR 0.99, 95% CI 0.65 to 1.52; 6 RCTs, N = 3000; GRADE moderate-quality).Exercise versus controlThe evidence for caesarean section (RR 0.86, 95% CI 0.63 to 1.16; 5 RCTs, N = 316; GRADE moderate quality) and perinatal death or serious morbidity composite was inconclusive (RR 0.56, 95% CI 0.12 to 2.61; 2 RCTs, N = 169; GRADE moderate-quality).Insulin versus oral therapyThe evidence for the following outcomes was inconclusive: pre-eclampsia (RR 1.14, 95% CI 0.86 to 1.52; 10 RCTs, N = 2060), caesarean section (RR 1.03, 95% CI 0.93 to 1.14; 17 RCTs, N = 1988), large-for-gestational age (average RR 1.01, 95% CI 0.76 to 1.35; 13 RCTs, N = 2352), and perinatal death or serious morbidity composite (RR 1.03; 95% CI 0.84 to 1.26; 2 RCTs, N = 760). GRADE assessment was moderate-quality for these outcomes.Insulin versus dietThe evidence for perinatal mortality was inconclusive (RR 0.74, 95% CI 0.41 to 1.33; 4 RCTs, N = 1137; GRADE moderate-quality).Insulin versus insulinThe evidence for insulin aspart versus lispro for risk of caesarean section was inconclusive (RR 1.00, 95% CI 0.91 to 1.09; 3 RCTs, N = 410; GRADE moderate quality).No conclusions possibleNo conclusions were possible for: lifestyle versus usual care (perineal trauma, postnatal depression, neonatal adiposity, number of antenatal visits/admissions); diet versus control (pre-eclampsia, caesarean section); myo-inositol versus placebo (hypoglycaemia); metformin versus glibenclamide (hypertensive disorders of pregnancy, pregnancy-induced hypertension, death or serious morbidity composite, insulin versus oral therapy (development of type 2 diabetes); intensive management versus routine care (IOL, large-for-gestational age); post- versus pre-prandial glucose monitoring (large-for-gestational age). The evidence ranged from moderate-, low- and very low-quality.

AUTHORS' CONCLUSIONS

Currently there is insufficient high-quality evidence about the effects on health outcomes of relevance for women with GDM and their babies for many of the comparisons in this overview comparing treatment interventions for women with GDM. Lifestyle changes (including as a minimum healthy eating, physical activity and self-monitoring of blood sugar levels) was the only intervention that showed possible health improvements for women and their babies. Lifestyle interventions may result in fewer babies being large. Conversely, in terms of harms, lifestyle interventions may also increase the number of inductions. Taking insulin was also associated with an increase in hypertensive disorders, when compared to oral therapy. There was very limited information on long-term health and health services costs. Further high-quality research is needed.

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.

Efficacy of Complementary Therapies in the Quality of Life of Breast Cancer Survivors

Breast cancer (BC) is the most common cancer diagnosed in women and the second most common cancer overall, ranking as the fifth cause of death from cancer. The chronicity of the disease produces long-term physiological and psychological manifestations, which adversely affect the quality of life of the individual. The primary treatment while managing cancer presents with various debilitating side effects. With the recent advances in treatment techniques that have improved the survival rate, patients suffer from continuing posttreatment complications. Patients seem to cope well with the stress of treatment of BC and sustain a normal life; however, the deterioration in physical well-being makes the patient functionally inefficient. Exercise has been proven to be an effective, safe, and feasible tool in combating the adverse effects of treatment, prevents complications and decreases the risk of BC-specific mortality. This review briefly presents an overview of the burden of the disease and its management strategies. Owing to the heterogeneity of the population and the multitude of therapies they receive, the response of each patient to treatment is different and so is the magnitude of adverse effects. The review discusses the late sequelae following treatment and evidence supporting the role of physical activity in their management. In conclusion, there is a need for personalized physical activity plans to be developed to suit the individual and their circumstances.

Planned birth at or near term for improving health outcomes for pregnant women with gestational diabetes and their infants

BACKGROUND

Gestational diabetes is a type of diabetes that occurs during pregnancy. Women with gestational diabetes are more likely to experience adverse health outcomes such as pre-eclampsia or polyhydramnios (excess amniotic fluid). Their babies are also more likely to have health complications such as macrosomia (birthweight > 4000 g) and being large-for-gestational age (birthweight above the 90th percentile for gestational age). Current clinical guidelines support elective birth, at or near term in women with gestational diabetes to minimise perinatal complications, especially those related to macrosomia.This review replaces a review previously published in 2001 that included "diabetic pregnant women", which has now been split into two reviews. This current review focuses on pregnant women with gestational diabetes and a sister review focuses on women with pre-existing diabetes (Type 1 or Type 2).

OBJECTIVES

To assess the effect of planned birth (either by induction of labour or caesarean birth), at or near term (37 to 40 weeks' gestation) compared with an expectant approach for improving health outcomes for women with gestational diabetes and their infants. The primary outcomes relate to maternal and perinatal mortality and morbidity.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (15 August 2017), and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised trials comparing planned birth, at or near term (37 to 40 weeks' gestation), with an expectant approach, for women with gestational diabetes. Cluster-randomised and non-randomised trials (e.g. quasi-randomised trials using alternate allocation) were also eligible for inclusion but none were identified.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

The findings of this review are based on a single trial involving 425 women with gestational diabetes. The trial compared induction of labour with expectant management (waiting for the spontaneous onset of labour in the absence of any maternal or fetal issues that may necessitate birth) in pregnant women with gestational diabetes at term. We assessed the overall risk of bias as being low for most domains, apart from performance, detection and attrition bias (for outcome perineum intact), which we assessed as being at high risk. It was an open-label trial, and women and healthcare professionals were not blinded.There were no clear differences between women randomised to induction of labour and women randomised to expectant management for maternal mortality or serious maternal morbidity (risk ratio (RR) 1.48, 95% confidence interval (CI) 0.25 to 8.76, one trial, 425 women); caesarean section (RR 1.06, 95% CI 0.64 to 1.77, one trial, 425 women); or instrumental vaginal birth (RR 0.81, 95% CI 0.45 to 1.46, one trial, 425 women). For the primary outcome of maternal mortality or serious maternal morbidity, there were no deaths in either group and serious maternal morbidity related to admissions to intensive care unit. The quality of the evidence contributing to these outcomes was assessed as very low, mainly due to the study having high risk of bias for some domains and because of the imprecision of effect estimates.In relation to primary neonatal outcomes, there were no perinatal deaths in either group. The quality of evidence for this outcome was judged as very low, mainly due to high risk of bias and imprecision of effect estimates. There were no clear differences in infant outcomes between women randomised to induction of labour and women randomised to expectant management: shoulder dystocia (RR 2.96, 95% CI 0.31 to 28.21, one trial, 425 infants, very low-quality evidence); large-for-gestational age (RR 0.53, 95% CI 0.28 to 1.02, one trial, 425 infants, low-quality evidence).There were no clear differences between women randomised to induction of labour and women randomised to expectant management for postpartum haemorrhage (RR 1.17, 95% CI 0.53 to 2.54, one trial, 425 women); admission to intensive care unit (RR 1.48, 95% CI 0.25 to 8.76, one trial, 425 women); and intact perineum (RR 1.02, 95% CI 0.73 to 1.43, one trial, 425 women). No infant experienced a birth trauma, therefore, we could not draw conclusions about the effect of the intervention on the outcomes of brachial plexus injury and bone fracture at birth. Infants of women in the induction-of-labour group had higher incidences of neonatal hyperbilirubinaemia (jaundice) when compared to infants of women in the expectant-management group (RR 2.46, 95% CI 1.11 to 5.46, one trial, 425 women).We found no data on the following prespecified outcomes of this review: postnatal depression, maternal satisfaction, length of postnatal stay (mother), acidaemia, intracranial haemorrhage, hypoxia ischaemic encephalopathy, small-for-gestational age, length of postnatal stay (baby) and cost.The authors of this trial acknowledge that it is underpowered for their primary outcome of caesarean section. The authors of the trial and of this review note that the CIs demonstrate a wide range, therefore making it inappropriate to draw definite conclusions.

AUTHORS' CONCLUSIONS

There is limited evidence to inform implications for practice. The available data are not of high quality and lack power to detect possible important differences in either benefit or harm. There is an urgent need for high-quality trials evaluating the effectiveness of planned birth at or near term gestation for women with gestational diabetes compared with an expectant approach.

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.

Exercise for pregnant women with gestational diabetes for improving maternal and fetal outcomes

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with both short- and long-term complications for the mother and her baby. Exercise interventions may be useful in helping with glycaemic control and improve maternal and infant outcomes.The original review on Exercise for diabetic pregnant women has been split into two new review titles reflecting the role of exercise for pregnant women with gestational diabetes and for pregnant women with pre-existing diabetes. Exercise for pregnant women with gestational diabetes for improving maternal and fetal outcomes (this review) Exercise for pregnant women with pre-existing diabetes for improving maternal and fetal outcomes OBJECTIVES: To evaluate the effects of exercise interventions for improving maternal and fetal outcomes in women with GDM.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (27 August 2016), ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (18th August 2016), and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing an exercise intervention with standard care or another intervention in pregnant women diagnosed with gestational diabetes. Quasi-randomised and cross-over studies, and studies including women with pre-existing type 1 or type 2 diabetes were not eligible for inclusion.

DATA COLLECTION AND ANALYSIS

All selection of studies, assessment of trial quality and data extraction was conducted independently by two review authors. Data were checked for accuracy.

MAIN RESULTS

We included 11 randomised trials, involving 638 women. The overall risk of bias was judged to be unclear due to lack of methodological detail in the included studies.For the mother, there was no clear evidence of a difference between women in the exercise group and those in the control group for the risk of pre-eclampsia as the measure of hypertensive disorders of pregnancy (risk ratio (RR) 0.31, 95% confidence interval (CI) 0.01 to 7.09; two RCTs, 48 women; low-quality evidence), birth by caesarean section (RR 0.86, 95% CI 0.63 to 1.16; five RCTs, 316 women; I2 = 0%; moderate-quality evidence), the risk of induction of labour (RR 1.38, 95% CI 0.71 to 2.68; one RCT, 40 women; low-quality evidence) or maternal body mass index at follow-up (postnatal weight retention or return to pre-pregnancy weight) (mean difference (MD) 0.11 kg/m2, 95% CI -1.04 to 1.26; three RCTs, 254 women; I2 = 0%; high-quality evidence). Development of type 2 diabetes, perineal trauma/tearing and postnatal depression were not reported as outcomes in the included studies.For the infant/child/adult, a single small (n = 19) trial reported no perinatal mortality (stillbirth and neonatal mortality) events in either the exercise intervention or control group (low-quality evidence). There was no clear evidence of a difference between groups for a mortality and morbidity composite (variously defined by trials, e.g. perinatal or infant death, shoulder dystocia, bone fracture or nerve palsy) (RR 0.56, 95% CI 0.12 to 2.61; two RCTs, 169 infants; I2 = 0%; moderate-quality evidence) or neonatal hypoglycaemia (RR 2.00, 95% CI 0.20 to 20.04; one RCT, 34 infants; low-quality evidence). None of the included trials pre-specified large-for-gestational age, adiposity (neonatal/infant, childhood or adulthood), diabetes (childhood or adulthood) or neurosensory disability (neonatal/infant) as trial outcomes.Other maternal outcomes of interest: exercise interventions were associated with both reduced fasting blood glucose concentrations (average standardised mean difference (SMD) -0.59, 95% CI -1.07 to -0.11; four RCTs, 363 women; I2 = 73%; T2 = 0.19) and a reduced postprandial blood glucose concentration compared with control interventions (average SMD -0.85, 95% CI -1.15 to -0.55; three RCTs, 344 women; I2 = 34%; T2 = 0.03).

AUTHORS' CONCLUSIONS

Short- and long-term outcomes of interest for this review were poorly reported. Current evidence is confounded by the large variety of exercise interventions. There was insufficient high-quality evidence to be able to determine any differences between exercise and control groups for our outcomes of interest. For the woman, both fasting and postprandial blood glucose concentrations were reduced compared with the control groups. There are currently insufficient data for us to determine if there are also benefits for the infant. The quality of the evidence in this review ranged from high to low quality and the main reason for downgrading was for risk of bias and imprecision (wide CIs, low event rates and small sample size). Development of type 2 diabetes, perineal trauma/tearing, postnatal depression, large-for-gestational age, adiposity (neonate/infant, childhood or adulthood), diabetes (childhood or adulthood) or neurosensory disability (neonate/infant) were not reported as outcomes in the included studies.Further research is required comparing different types of exercise interventions with control groups or with another exercise intervention that reports on both the short- and long-term outcomes (for both the mother and infant/child) as listed in this review.

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.

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.

Gestational diabetes mellitus may be associated with increased risk of breast cancer

Background:

Although a positive association between type 2 diabetes and breast cancer has been reported, an association with gestational diabetes mellitus (GDM) is less clear.

Methods:

The Sister Study enroled 50 884 women aged 35–74 years, from 2003 through 2009. Cox proportional hazards models were used to estimate breast cancer risk in relation to GDM.

Results:

Ever having GDM was not associated with breast cancer overall (hazards ratio (HR)=1.10, 95% confidence interval (CI)=0.88–1.36), but there was a suggestive association between ever having a GDM pregnancy and oestrogen receptor (ER) -negative breast cancer (HR=1.73, 95% CI=0.98–3.06). However, having 2 or more GDM pregnancies was associated with overall breast cancer risk 1.68 (95% CI=1.15–2.44) and with ER-positive breast cancer (HR=1.81, 95% CI=1.10–2.98), which was supported by sensitivity analyses. Results were similar when analyses were stratified by whether or not type 2 diabetes had developed after GDM.

Conclusions:

Women with multiple GDM pregnancies had a higher incidence of breast cancer, suggesting that such women could benefit from increased surveillance for breast cancer.

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.

Modifiable risk factors for gestational diabetes recurrence

The literature on risk factors for gestational diabetes mellitus recurrence is inconsistent and sometimes contradictory. The importance of inter-pregnancy interval and parity, remains unclear. We aimed to explore controversial risk factors for gestational diabetes mellitus recurrence, especially the modifiable ones, and to develop a prediction model in a cohort of women with gestational diabetes mellitus. A retrospective, population-based, cross-sectional cohort study was performed. The study included 788 women with gestational diabetes mellitus that delivered between 1991-2012 and had consecutive deliveries at a university affiliated hospital in Israel. Women with pre-existing diabetes were excluded. Factors associated with gestational diabetes mellitus recurrence were examined using log-binomial models to estimate prevalence ratios with 95 % confidence intervals. Multivariate analysis revealed that both inter-pregnancy interval and multiparity were significant risk factors for gestational diabetes mellitus recurrence. Other significant risk factors were maternal age, gestational diabetes mellitus diagnosis week, oral glucose tolerance test values, body mass index gain between pregnancies and insulin use; the latter and multiparity had the strongest effect size (PR ≥ 1.2). Among multiparous women, the association between inter-pregnancy interval and gestational diabetes mellitus recurrence was significantly lower (P = 0.0004) compared with primiparous women (PR = 1.11 [95 % CI 1.09-1.13] versus PR = 1.17 [95 % CI 1.15-1.20], respectively). The model we developed, predicts that reducing the inter-pregnancy interval and weight gain between pregnancies can reduce substantially the risk of gestational diabetes mellitus recurrence. The results suggest that weight gain and inter-pregnancy interval are modifiable risk factors for gestational diabetes mellitus recurrence. Our model could assist physicians in advising women with gestational diabetes mellitus in reducing the risk of recurrent gestational diabetes mellitus during subsequent pregnancies.

Metformin - a potentially effective drug for gestational diabetes mellitus: a systematic review and meta-analysis

Metformin has been gradually used in the management of gestational diabetes mellitus (GDM). In order to prove the safety and efficacy of metformin used in pregnancy, we searched several databases for the reports of randomized trials comparing insulin and metformin used in GDM and conducted a meta-analysis. Data showed the rates of neonatal large for gestational age, cesarean section, neonatal respiratory distress and preterm birth were similar in both groups. Maternal glycated hemoglobin-% at gestational week 36-37 was significantly lower in metformin group, indicating good glycemic control of metformin. Maternal weight gain since enrollment to gestational week 36-37 was also lower in metformin group, making metformin worth using even when metformin is insufficient and supplementary insulin is needed. Data also showed that metformin significantly reduced the gestational hypertension complications in GDM patients, probably by reducing the endothelial activation and maternal inflammatory response of insulin resistance. Although metformin can cross the placenta, it is less likely to cause severe neonatal hypoglycemia compared with insulin since it neither stimulates pancreatic insulin release nor increases circulating insulin levels. According to most maternal and neonatal outcomes, metformin is an effective and safe alternative to insulin for GDM patients.

Risk factors of gestational diabetes mellitus recurrence: a meta-analysis

The literature regarding risk factors for gestational diabetes mellitus (GDM) recurrence is inconsistent. We aimed to assess the effect sizes of risk factors of GDM recurrence. We searched electronic databases (1970-2015) and bibliographies for studies that included women with GDM (index pregnancy) who had a consecutive birth. We compared the risk factors among women with and without GDM recurrence. Differences in variables measured on a continuous scale were estimated using the weighted mean difference (WMD). The standardized mean difference (SMD) was used to rate the pooled effects. For categorical variables, the pooled odds ratio was estimated. Cochran's Q test of heterogeneity was used to choose the model for estimating the pooled effects. Fourteen cross-sectional cohort studies (63 % with sample size ≥100) were considered. Women with GDM recurrence were older (by 1.32 years; P < 0.0001), heavier (by 1.82 BMI; P = 0.013), had higher 100-g oral glucose tolerance test (OGTT) levels (Fasting: by 8.42 mg/dl, 1-h: by 13.0 mg/dl, 2-h: by 18.2 mg/dl, 3-h: by 11.3 mg/dl; P < 0.0001 for all) and higher weight gain between pregnancies (by 3.24 kg; P = 0.012). The SMD effect sizes were relatively small (between 0.3 and 0.4), but weight gain between pregnancies had a medium-large effect size (SMD = 0.8). Insulin use, multiparity, and fetal macrosomia were all associated with GDM recurrence (OR 6.3 [95 % CI 3.9-10.2], OR 1.88 [95 % CI 1.09-3.24] and OR 1.63 [95 % CI 1.25-2.13], respectively). GDM recurrence is multifactorial. Stronger risk factors include insulin use, BMI, multiparity, macrosomia, and weight gain between pregnancies.

Different intensities of glycaemic control for women with gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) has major short- and long-term implications for both the mother and her baby. GDM is defined as a carbohydrate intolerance resulting in hyperglycaemia or any degree of glucose intolerance with onset or first recognition during pregnancy from 24 weeks' gestation onwards and which resolves following the birth of the baby. Rates for GDM can be as high as 25% depending on the population and diagnostic criteria used and rates are increasing globally. Risk factors associated with GDM include advanced maternal age, obesity, ethnicity, family history of diabetes, and a previous history of GDM, macrosomia or unexplained stillbirth. There is wide variation internationally in glycaemic treatment target recommendations for women with GDM that are based on consensus rather than high-quality trials.

OBJECTIVES

To assess the effect of different intensities of glycaemic control in pregnant women with GDM on maternal and infant health outcomes.

SEARCH METHODS

We searched the Cochrane Pregancy and Childbirth Group's Trials Register (31 January 2016), ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (1 February 2016) and reference lists of the retrieved studies.

SELECTION CRITERIA

We included one randomised controlled trial. Cluster-randomised and quasi-randomised controlled trials were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

We used the methods described in the Cochrane Handbook for Systematic Reviews of Interventions for carrying out data collection, assessing study quality and analysing results. Two review authors independently assessed trial eligibility for inclusion, evaluated methodological quality and extracted data for the one included study. We sought additional information from one trial author but had no response. We assessed the quality of evidence for selected outcomes using the GRADE approach.

MAIN RESULTS

We included one Canadian trial of 180 women, recruited between 20 to 32 weeks' gestation, who had been diagnosed with GDM. Data from 171 of the 180 women were published as a conference abstract and no full report has been identified. The overall risk of bias of the single included study was judged to be unclear.The included trial did not report on any of this review's primary outcomes. For the mother, these were hypertension disorders of pregnancy or subsequent development of type 2 diabetes. For the infant, our primary outcomes were (perinatal (fetal and neonatal) mortality; large-for-gestational age; composite of death or severe morbidity or later childhood neurosensory disability).The trial did report data relating to some of this review's secondary outcomes. There was no clear difference in caesarean section rates for women assigned to using strict glycaemic targets (pre-prandial 5.0 mmol/L (90 mg/L) and at one-hour postprandial 6.7 mmol/L (120 mg/dL)) (28/85, 33%) when compared with women assigned to using liberal glycaemic targets (pre-prandial 5.8 mmol/L (103 mg/dL) and at one-hour postprandial 7.8 mmol/L (140 mg/dL)) (21/86, 24%) (risk ratio (RR) 1.35, 95% confidence interval (CI) 0.83 to 2.18, one trial, 171 women; very low quality). Using the GRADE approach, we found the quality of the evidence to bevery low for caesarean section due to poor reporting of risk of bias, imprecision and publication bias. Strict glycaemic targets were associated with an increase in the use of pharmacological therapy (identified as the use of insulin in this study) (33/85; 39%) compared with liberal glycaemic targets (18/86; 21%) (RR 1.85, 95% CI 1.14 to 3.03; one trial, 171 women). CIs are wide suggesting imprecision and caution is required when interpreting the data. No other secondary maternal outcome data relevant to this review were reported. For the infant, there were no clear differences between the groups of women receiving strict and liberal glycaemic targets for macrosomia (birthweight greater than 4000 g) (RR 1.35, 95% CI 0.31 to 5.85, one trial, 171 babies); small-for-gestational age (RR 1.12, 95% CI 0.48 to 2.63, one trial, 171 babies); birthweight (mean difference (MD) -92.00 g, 95% CI -241.97 to 57.97, one trial, 171 babies) or gestational age (MD -0.30 weeks, 95% CI -0.73 to 0.13, one trial, 171 babies). Adverse effects data were not reported. No other secondary neonatal outcomes relevant to this review were reported.

AUTHORS' CONCLUSIONS

This review is based on a single study (involving 180 women) with an unclear risk of bias. The trial (which was only reported in a conference abstract) did not provide data for any of this review's primary outcomes but did provide data for a limited number of our secondary outcomes. There is insufficient evidence to guide clinical practice for targets for glycaemic control for women with GDM to minimise adverse effects on maternal and fetal health. Glycaemic target recommendations from international professional organisations for maternal glycaemic control vary widely and are reliant on consensus given the lack of high-quality evidence.Further high-quality trials are needed, and these should compare different glycaemic targets for guiding treatment of women with GDM, assess both short-term and long-term health outcomes for women and their babies, include women's experiences and assess health services costs. Four studies are ongoing.

Prediction and prevention of Gestational Diabetes: an update of recent literature

A diagnosis of Gestational Diabetes (GDM) confers adverse risk to the health of the mother and fetus both in pregnancy and later life. The background rate in pregnancy varies between 2 and 14% with incidences reported to be as high as 40% in obese populations. GDM diagnoses are escalating because of rising numbers of overweight and obesity in the reproductive age group but also because of different screening and diagnostic criteria. Lifestyle modification in those diagnosed with GDM has been proven to be an effective treatment in attenuating the metabolic dysregulation associated with this and potentially avoiding the need for medical therapy with either metformin or insulin. Emerging evidence in previous years suggests lifestyle interventions (dietary±physical activity and behavior modification) either pre-pregnancy or antenatally may reduce the incidence of GDM. The first trimester is also becoming an important interrogation period for the prediction of many adverse obstetric outcomes including abnormal glucose metabolism. This review outlines the most contemporary evidence on the prediction and non-pharmacological antenatal prevention strategies used for Gestational Diabetes.

Gestational diabetic transcriptomic profiling of microdissected human trophoblast

Gestational diabetes mellitus (GDM), the most common metabolic complication of pregnancy, is influenced by the placenta, and its prevalence directly increases with obesity. Therefore, to define the aetiology of GDM requires that the confounding influence of obesity and the heterogeneous nature of the placenta impairing accurate quantitative studies be accounted for. Using laser capture microdissection (LCM), we optimized RNA extraction from human placental trophoblast, the metabolic cellular interface between mother and foetus. This allowed specific transcriptomic profiling of trophoblast isolated from GDM, and obese and normal human placentae. Genome-wide gene expression analysis was performed on the RNA extracted from the trophoblast of GDM and obese and normal placentae. Forty-five differentially expressed genes (DEGs) specifically discriminated GDM from matched obese subjects. Two genes previously linked with GDM, pregnancy specific beta-1 glycoprotein 6 (PSG6) and placental system A sodium-dependent transporter system (SLC38A1), were significantly increased in GDM. A number of these DEGs (8 ubiquitin-conjugating enzymes (UBE) splice variants (UBE2D3 variants 1, 3, 4, 5, 6, 7, and 9) and UBE2V1 variant 4)) were involved in RNA processing and splicing, and a significant number of the DEGs, including the UBE variants, were associated with increased maternal fasting plasma glucose.It is concluded that DEGs discriminating GDM from obese subjects were pinpointed. Our data indicate a biological link between genes involved in RNA processing and splicing, ubiquitination, and fasting plasma glucose in GDM taking into account obesity as the confounder.

Assessing use of a printed lifestyle intervention tool by women with borderline gestational diabetes and their achievement of diet and exercise goals: a descriptive study

BACKGROUND

The purpose of this study is to assess use of a booklet by pregnant women to record and assist dietary and lifestyle changes; to describe diet and exercise goals set during the initial lifestyle discussions; and to assess achievement of goals.

METHODS

Participants were women with borderline gestational diabetes who received a printed pregnancy record booklet, as part of a randomised trial, to record and set monthly goals for diet and exercise. Outcomes included women's use of the booklets and their achievement of dietary and exercise goals after 1 month.

RESULTS

Fifty-six women returned their used pregnancy record booklets and were included in this study. These women set a total of 197 dietary goals and 65 exercise goals. In the first month, over 80% of dietary goals that targeted grains, dairy and overall diet were achieved, but only 20-30% of goals about vegetables, and foods high in fat, sugar and/or salt were achieved. After 1 month, women had achieved 86.4% of their exercise goals to maintain their current level of activity, but only 25.0 % exercise goals to increase walking during pregnancy.

CONCLUSIONS

Women who used pregnancy record booklets reported good achievement rates for goals related to grains, fruits, dairy and overall diet, but they were less likely to be successful in achieving goals to increase intake of vegetables, and limit foods that high in fat, sugar and/or salt. Maintaining an active lifestyle during pregnancy was feasible for women although increases in physical activity were less often achieved. Using a pregnancy record booklet may be helpful in assisting and encouraging behavioural changes, although further investigations of long-term effects and in different populations are warranted.

Identifying Key Intervention Opportunities During a Pregnancy Complicated by Diabetes: a Review of Acute Complications of Diabetes During Pregnancy

Diabetes in pregnancy is associated with significant and sometimes devastating acute complications. It is important that all health care providers are aware of possible complications at each stage of pregnancy so that we can prevent these complications whenever possible and reduce morbidity when they do occur. Most complications associated with diabetes during pregnancy have reduced incidence when blood glucose and blood pressure are optimally controlled. Yet, it is always best to try to optimize diabetes and any comorbidities prior to conception.

The prevalence of gestational diabetes mellitus recurrence--effect of ethnicity and parity: a metaanalysis

Reports on the gestational diabetes mellitus (GDM) recurrence rate have been highly variable. Our objectives were to examine the possible causes of GDM recurrence rate variability and to obtain pooled estimates in subgroups. We have carried out a systematic review and metaanalysis based on the Metaanalysis Of Observational Studies in Epidemiology statement. We identified papers published from 1973 to September 2014. We identified papers using Medline (PubMed and Ovid), ClinicalTrials.gov and Google Scholar databases, and published references. We included only English-language, population-based studies that reported specified GDM criteria and GDM recurrence rate. A total of 18 eligible studies with 19,053 participants were identified. We used the Cochrane's Q test of heterogeneity to choose the model for estimating the pooled GDM recurrence rate. Metaregression was also used to explore the possible causes of variability between studies. The pooled GDM recurrence rate was 48% (95% confidence interval, 41-54%). A significant association between ethnicity and GDM recurrence rate was found (P = .02). Non-Hispanic whites had lower recurrence rate compared with other ethnicities (39% and 56%, respectively). Primiparous women had a lower recurrence rate compared with multiparous women (40% and 73%, respectively; P < .0001) No evidence for association between family history of diabetes and GDM recurrence was found. The overall GDM recurrence rate is high. Non-Hispanic whites and primiparous women have substantially lower GDM recurrence rates, which contributes to the variability between studies. Because no association between family history of diabetes and GDM recurrence was found, the large differences between ethnic groups may have also resulted from nongenetic factors. Thus, intervention programs could reduce the GDM recurrence rates.

Prevention of gestational diabetes in pregnant women with risk factors for gestational diabetes: a systematic review and meta-analysis of randomised trials

BACKGROUND

Gestational diabetes mellitus can be defined as 'glucose intolerance or hyperglycaemia with onset or first recognition during pregnancy.'

OBJECTIVE

The objective of our systematic review was to see if there was any intervention that could be used for primary prevention of gestational diabetes mellitus in women with risk factors for gestational diabetes mellitus.

SEARCH STRATEGY

Major databases were searched from 1966 to Aug 2012 without language restriction.

SELECTION CRITERIA

Randomised trials comparing intervention with standard care in women with risk factors for gestational diabetes were included. Meta-analysis was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement. The primary outcome assessed was the incidence of gestational diabetes.

DATA COLLECTION AND ANALYSIS

Data from included trials were extracted independently by two authors and analysed using Rev-Man 5.

MAIN RESULTS

A total of 2422 women from 14 randomised trials were included; which compared diet (four randomised trials), exercise (three randomised trials), lifestyle changes (five randomised trials) and metformin (two randomised trials) with standard care in women with risk factors for gestational diabetes mellitus. Dietary intervention was associated with a statistically significantly lower incidence of gestational diabetes (Odds ratio 0.33, 95% CI 0.14 to 0.76) and gestational hypertension (Odds ratio 0.28, 95% CI 0.09, 0.86) compared to standard care. There was no statistically significant difference in the incidence of gestational diabetes mellitus or in the secondary outcomes with exercise, lifestyle changes or metformin use compared to standard care.

CONCLUSIONS

The use of dietary intervention has shown a statistically significantly lower incidence of gestational diabetes mellitus and gestational hypertension compared to standard care in women with risk factors for gestational diabetes mellitus.

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.