Gestational diabetes mellitus and adverse maternal and perinatal outcomes in twin and singleton pregnancies: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to assess the risk of adverse maternal and perinatal complications between twin and singleton pregnancies affected by gestational diabetes mellitus and the respective group without gestational diabetes mellitus (controls). DATA SOURCES: A literature search was performed using MEDLINE, Embase, and Cochrane from January 1980 to May 2023. STUDY ELIGIBILITY CRITERIA: Observational studies reporting maternal and perinatal outcomes in singleton and/or twin pregnancies with gestational diabetes mellitus vs controls were included. METHODS: This was a systematic review and meta-analysis. Pooled estimate risk ratios with 95% confidence intervals were generated to determine the likelihood of adverse pregnancy outcomes between twin and singleton pregnancies with and without gestational diabetes mellitus. Heterogeneity among studies was evaluated in the model and expressed using the I2 statistic. A P value of <.05 was considered statistically significant. The meta-analyses were performed using Review Manager (RevMan Web). Version 5.4. The Cochrane Collaboration, 2020. Meta-regression was used to compare relative risks between singleton and twin pregnancies. The addition of multiple covariates into the models was used to address the lack of adjustments. RESULTS: Overall, 85 studies in singleton pregnancies and 27 in twin pregnancies were included. In singleton pregnancies with gestational diabetes mellitus, compared with controls, there were increased risks of hypertensive disorders of pregnancy (relative risk, 1.85; 95% confidence interval, 1.69-2.01), induction of labor (relative risk, 1.36; 95% confidence interval, 1.05-1.77), cesarean delivery (relative risk, 1.31; 95% confidence interval, 1.24-1.38), large-for-gestational-age neonate (relative risk, 1.61; 95% confidence interval, 1.46-1.77), preterm birth (relative risk, 1.36; 95% confidence interval, 1.27-1.46), and admission to the neonatal intensive care unit (relative risk, 1.43; 95% confidence interval, 1.38-1.49). In twin pregnancies with gestational diabetes mellitus, compared with controls, there were increased risks of hypertensive disorders of pregnancy (relative risk, 1.69; 95% confidence interval, 1.51-1.90), cesarean delivery (relative risk, 1.10; 95% confidence interval, 1.06-1.13), large-for-gestational-age neonate (relative risk, 1.29; 95% confidence interval, 1.03-1.60), preterm birth (relative risk, 1.19; 95% confidence interval, 1.07-1.32), and admission to the neonatal intensive care unit (relative risk, 1.20; 95% confidence interval, 1.09-1.32) and reduced risks of small-for-gestational-age neonate (relative risk, 0.89; 95% confidence interval, 0.81-0.97) and neonatal death (relative risk, 0.50; 95% confidence interval, 0.39-0.65). When comparing relative risks in singleton vs twin pregnancies, there was sufficient evidence to suggest that twin pregnancies have a lower relative risk of cesarean delivery (P=.003), have sufficient adjustment for confounders, and have lower relative risks of admission to the neonatal intensive care unit (P=.005), stillbirths (P=.002), and neonatal death (P=.001) than singleton pregnancies. CONCLUSION: In both singleton and twin pregnancies, gestational diabetes mellitus was associated with an increased risk of adverse maternal and perinatal outcomes. In twin pregnancies, gestational diabetes mellitus may have a milder effect on some adverse perinatal outcomes and may be associated with a lower risk of neonatal death.

The accuracy of haemoglobin A1c as a screening and diagnostic test for gestational diabetes: a systematic review and meta-analysis of test accuracy studies.

PURPOSE OF REVIEW: Gestational diabetes mellitus (GDM) is associated with adverse pregnancy complications. Accurate screening and diagnosis of gestational diabetes are critical to treatment, and in a pandemic scenario like coronavirus disease 2019 needing a simple test that minimises prolonged hospital stay. We undertook a meta-analysis on the screening and diagnostic accuracy of the haemoglobin A1c (HbA1c) test in women with and without risk factors for gestational diabetes. RECENT FINDINGS: Unlike the oral glucose tolerance test, the HbA1c test is simple, quick and more acceptable. There is a growing body of evidence on the accuracy of HbA1c as a screening and diagnostic test for GDM. We searched Medline, Embase and Cochrane Library and selected relevant studies. Accuracy data for different thresholds within the final 23 included studies (16 921 women) were pooled using a multiple thresholds model. Summary accuracy indices were estimated by selecting an optimal threshold that optimises either sensitivity or specificity according to different scenarios. SUMMARY: HbA1c is more useful as a specific test at a cut-off of 5.7% (39 mmol/mol) with a false positive rate of 10%, but should be supplemented by a more sensitive test to detect women with GDM.

Metformin in the prevention of type 2 diabetes after gestational diabetes in postnatal women (OMAhA): a UK multicentre randomised, placebo-controlled, double-blind feasibility trial with nested qualitative study.

OBJECTIVE: To determine the feasibility of a definitive trial of metformin to prevent type 2 diabetes in the postnatal period in women with gestational diabetes. DESIGN: A multicentre, placebo-controlled, double-blind randomised feasibility trial with qualitative evaluation. SETTING: Three inner-city UK National Health Service hospitals in London. PARTICIPANTS: Pregnant women with gestational diabetes treated with medication. INTERVENTIONS: 2 g of metformin (intervention) or placebo (control) from delivery until 1 year postnatally. PRIMARY OUTCOME MEASURES: Rates of recruitment, randomisation, follow-up, attrition and adherence to the intervention. SECONDARY OUTCOME MEASURES: Preliminary estimates of glycaemic effects, qualitative exploration, acceptability of the intervention and costs. RESULTS: Out of 302 eligible women, 57.9% (175/302) were recruited. We randomised 82.3% (144/175) of those recruited, with 71 women in the metformin group and 73 women in the placebo group. Of the participants remaining in the study and providing any adherence information, 54.1% (59/109) took at least 75% of the target intervention dose; the overall mean adherence was 64% (SD 33.6). Study procedures were found to be acceptable to women and healthcare professionals. An increased perceived risk of developing type 2 diabetes, or a positive experience of taking metformin during pregnancy, encouraged participation and adherence to the intervention. Barriers to adherence included disruption to the medication schedule caused by the washout periods ahead of each study visit or having insufficient daily reminders. CONCLUSIONS: It is feasible to run a full-scale definitive trial on the effectiveness of metformin to prevent type 2 diabetes in women with gestational diabetes, during the early postnatal period. Adherence and engagement with the study could be improved with more regular reminders and potentially the addition of ongoing educational or peer support to reinforce messages around type 2 diabetes prevention. TRIAL REGISTRATION NUMBER: ISRCTN20930880.

Type 1 Diabetes in Pregnancy: A Review of Complications and Management.

BACKGROUND: Pre-gestational diabetes can pose significant risk to the mother and infant, thus requiring careful counselling and management. Since Saint Vincent's declaration in 1989, adverse maternal and fetal outcomes, such as preeclampsia, perinatal mortality, congenital anomalies, and macrosomia, continue to be associated with type 1 diabetes. Although pregnancy is not considered an independent risk factor for the development of new onset microvascular complications, it is known to exacerbate pre-existing microvascular disease. Strict glycaemic control is the optimal management for pre-existing type 1 diabetes in pregnancy, as raised HbA1C is associated with increased risk of maternal and fetal complications. More recently, time in range on Continuous Glucose Monitoring glucose profiles has emerged as another useful evidence-based marker of fetal outcomes. OBJECTIVES: This review summarises the complications associated with pre-gestational type 1 diabetes, appropriate evidence-based management, including preparing for pregnancy, intrapartum and postpartum care. METHODS: A structured search of the PubMed and Cochrane databases was conducted. Peer-reviewed articles about complications and management guidelines on pre-gestational type 1 diabetes were selected and critically appraised. RESULTS: One hundred and twenty-three manuscripts were referenced and appraised in this review, and international guidelines were summarised. CONCLUSION: This review provides a comprehensive overview of the recurring themes in the literature pertaining to type 1 diabetes in pregnancy: maternal and fetal complications, microvascular disease progression, and an overview of current guideline-specific management.

Myo-inositol nutritional supplement for prevention of gestational diabetes (EMmY): a randomised, placebo-controlled, double-blind pilot trial with nested qualitative study.

OBJECTIVES: To determine the feasibility and acceptability of conducting a randomised trial on the effects of myo-inositol in preventing gestational diabetes in high-risk pregnant women. DESIGN: A multicentre, double-blind, placebo-controlled, pilot randomised trial with nested qualitative evaluation. SETTING: Five inner city UK National Health Service hospitals PARTICIPANTS: Multiethnic pregnant women at 12+0 and 15+6 weeks' gestation with risk factors for gestational diabetes. INTERVENTIONS: 2 g of myo-inositol or placebo, both included 200 µg folic acid, twice daily until delivery. PRIMARY OUTCOME MEASURES: Rates of recruitment, randomisation, adherence and follow-up. SECONDARY OUTCOME MEASURES: Glycaemic indices (including homoeostatic model assessment-insulin resistance HOMA-IR), gestational diabetes (diagnosed using oral glucose tolerance test at 28 weeks and by delivery), maternal, perinatal outcomes, acceptability of intervention and costs. RESULTS: Of the 1326 women screened, 58% (773/1326) were potentially eligible, and 27% (205/773) were recruited. We randomised 97% (198/205) of all recruited women (99 each in intervention and placebo arms) and ascertained outcomes in 90% of women (178/198) by delivery. The mean adherence was 52% (SD 44) at 28 weeks' and 34% (SD 41) at 36 weeks' gestation. HOMA-IR and serum insulin levels were lower in the myo-inositol vs placebo arm (mean difference -0.6, 95% CI -1.2 to 0.0 and -2.69, 95% CI -5.26 to -0.18, respectively). The study procedures were acceptable to women and healthcare professionals. Women who perceived themselves at high risk of gestational diabetes were more likely to participate and adhere to the intervention. The powder form of myo-inositol and placebo, along with nausea in pregnancy were key barriers to adherence. CONCLUSIONS: A future trial on myo-inositol versus placebo to prevent gestational diabetes is feasible. The intervention will need to be delivered in a non-powder form to improve adherence. There is a signal for efficacy in reducing insulin resistance in pregnancy with myo-inositol. TRIAL REGISTRATION NUMBER: ISRCTN48872100.

ENDOCRINOLOGY IN THE TIME OF COVID-19: Diagnosis and management of gestational diabetes mellitus.

The COVID-19 pandemic has required rapid transformation and adaptation of healthcare services. Women with gestational diabetes mellitus (GDM) are one of the largest high-risk groups accessing antenatal care. In reformulating the care offered to those with GDM, there is a need to balance the sometimes competing requirement of lowering the risk of direct viral transmission against the potential adverse impact of service changes. We suggest pragmatic options for screening of GDM in a pandemic setting based on blood tests, and risk calculators applied to underlying risk factors. Alternative models for antenatal care provision for women with GDM, including targeting high-risk groups, early lifestyle interventions and remote monitoring are provided. Testing options and their timing for postpartum screening in women who had GDM are also considered. Our suggestions are only applicable in a pandemic scenario, and usual guidelines and care pathways should be re-implemented as soon as possible and appropriate.

Effectiveness and acceptability of myo-inositol nutritional supplement in the prevention of gestational diabetes (EMmY): a protocol for a randomised, placebo-controlled, double-blind pilot trial.

INTRODUCTION: Gestational diabetes increases maternal and offspring complications in pregnancy and cardiovascular complications in the long term. The nutritional supplement myo-inositol may prevent gestational diabetes; however, further evaluation is required, especially in multiethnic high-risk mothers. Our pilot trial on myo-inositol to prevent gestational diabetes will evaluate trial processes, assess acceptability to mothers and obtain preliminary estimates of effect and cost data prior to a large full-scale trial. METHODS AND ANALYSIS: EMmY is a multicentre, placebo-controlled, double-blind, pilot, randomised trial, with qualitative evaluation. We will recruit pregnant women at 12-15+6 weeks' gestation, with gestational diabetes risk factors, from five maternity units in England between 2018 and 2019. We will randomise 200 women to take either 2 g of myo-inositol powder (intervention) or placebo, twice daily until delivery. We will assess rates of recruitment, randomisation, adherence to intervention and follow-up. Gestational diabetes will be diagnosed at 24-28 weeks as per the National Institute for Health and Care Excellence (NICE) criteria (fasting plasma glucose: ≥5.6 mmol/L and 2-hour plasma glucose: ≥7.8 mmol/L). We will assess the effects of myo-inositol on glycaemic indices at 28 weeks and on other maternal, fetal and neonatal outcomes at postnatal discharge. Qualitative evaluation will explore the acceptability of the trial and the intervention among women and healthcare professionals. Cost data and health-related quality of life measures will be captured. We will summarise feasibility outcomes using standard methods for proportions and other descriptive statistics, and where appropriate, report point estimates of effect sizes (eg, mean differences and relative risks) and associated 95% CIs. ETHICS AND DISSEMINATION: Ethical approval was obtained through the London Queen Square Research Ethics Committee (17/LO/1741). Study findings will be submitted for publication in peer-reviewed journals. Newsletters will be made available to participants, healthcare professionals and members of Katie's Team (a patient and public advisory group) to disseminate. TRIAL REGISTRATION NUMBER: ISRCTN48872100. PROTOCOL VERSION AND DATE: Version 4.0, 15 January 2018.

The Endocrine and Metabolic Characteristics of a Large Bardet-Biedl Syndrome Clinic Population.

Context: Bardet-Biedl syndrome (BBS) is a rare autosomal recessive disorder in which previous reports have described obesity and a metabolic syndrome. Objective: We describe the endocrine and metabolic characteristics of a large BBS population compared with matched control subjects. Design: We performed a case-control study. Setting: This study was performed at a hospital clinic. Patients: Study patients had a clinical or genetic diagnosis of BBS. Main Outcome Measurements: Our study determined the prevalence of a metabolic syndrome in our cohort. Results: A total of 152 subjects were studied. Eighty-four (55.3%) were male. Mean (± standard deviation) age was 33.2 ± 1.0 years. Compared with age-, sex-, and body mass index-matched control subjects, fasting glucose and insulin levels were significantly higher in subjects with BBS (glucose: BBS, 5.2 ± 1.2 mmol/L vs control, 4.9 ± 0.9 mmol/L, P = 0.04; insulin: BBS, 24.2 ± 17.0 pmol/L vs control, 14.2 ± 14.8 pmol/L, P < 0.001). Serum triglycerides were significantly higher in subjects with BBS (2.0 ± 1.2 mmol/L) compared with control subjects (1.3 ± 0.8 mmol/L; P < 0.001), but total cholesterol, high-density lipoprotein, and low-density lipoprotein were similar in both groups. Systolic blood pressure was higher in the BBS group (BBS, 135 ± 18 mm Hg vs control subjects, 129 ± 16 mm Hg; P = 0.02). Alanine transaminase was raised in 34 (26.8%) subjects with BBS, compared with five (8.9%) control subjects (P = 0.01). The rate of metabolic syndrome, determined using International Diabetes Federation criteria, was significantly higher in the BBS group (54.3%) compared with control subjects (26% P < 0.001). Twenty-six (19.5%) of male subjects with BBS were hypogonadal (serum testosterone, 9.9 ± 5.3 mmol/L), but significant pituitary abnormalities were uncommon. Subclinical hypothyroidism was present in 24 of 125 (19.4%) patients with BBS, compared with 3 of 65 (4.6%) control subjects (P = 0.01). Conclusions: Insulin resistance and the metabolic syndrome are increased in adult patients with BBS compared with matched control subjects. Increased subclinical hypothyroidism in the BBS cohort needs further investigation.

Postpartum care of women with gestational diabetes: survey of healthcare professionals.

OBJECTIVE: To assess the knowledge and practices of healthcare professionals on the postpartum care of women with gestational diabetes. STUDY DESIGN: We surveyed 106 healthcare professionals including obstetricians, diabetologists, general practitioners and midwives in East London and West Midlands in England (September 2014). The questionnaire assessed postpartum screening practices, care provision, future risk and strategies to prevent diabetes in women with gestational diabetes. RESULTS: The response rate was 87% (92/106). Nearly all respondents offered advice on diet (99%; CI 95%, 100%) and exercise (92%; CI 85%, 97%) postnatally in women with diagnosis of gestational diabetes. The preferred screening time for diabetes was 6 weeks to 3 months postpartum (76%; CI 66%, 85%). Overall, oral glucose tolerance test was the preferred test (57%; CI 46%, 67%), although general practitioners preferred fasting glucose (50%; CI 33%, 67%) and glycated hemoglobin (47%; CI 30%, 64%). Most midwives (81%, 17/21) and obstetricians (52%, 11/21) either underestimated or were unsure of the future risk of diabetes. There was lack of consensus on responsibility for immediate postpartum screening. CONCLUSION: The survey highlights the need for improved awareness of future risk of diabetes in women with gestational diabetes, consensus on optimal postpartum screening and identification of the main healthcare provider responsible for further management. This is particularly important for areas of social deprivation.