Gestational diabetes mellitus (GDM) is a frequent medical complication during pregnancy. This is partly due to the increasing prevalence of obesity in women of childbearing age. Since bariatric surgery is currently the most successful way to achieve maintained weight loss, increasing numbers of obese women of childbearing age receive bariatric surgery. Bariatric surgery performed before pregnancy significantly reduces the risk to develop GDM but the risk is generally still higher compared to normal weight pregnant women. Women after bariatric surgery therefore still require screening for GDM. However, screening for GDM is challenging in pregnant women after bariatric surgery. The standard screening tests such as an oral glucose tolerance test are often not well tolerated and wide variations in glucose excursions make the diagnosis difficult. Capillary blood glucose measurements may currently be the most acceptable alternative for screening in pregnancy after bariatric surgery. In addition, pregnant women after bariatric surgery have an increased risk for small neonates and need careful nutritional and foetal monitoring. In this review, we address the risk to develop GDM after bariatric surgery, the challenges to screen for GDM and the management of women with GDM after bariatric surgery.

Aims To determine the impact of depressive symptoms on pregnancy outcomes and postpartum quality of life in women with gestational diabetes mellitus (GDM) and normal glucose tolerance (NGT). Methods 1843 women from a prospective cohort study received universal GDM screening with an oral glucose tolerance test (OGTT). The Center for Epidemiologic Studies–Depression questionnaire was completed before GDM diagnosis was communicated and in GDM women in early postpartum. All participants completed the 36-Item Short Form Health Survey (SF-36) health survey postpartum. Results Women who developed GDM (231; 12.5%) had significantly more often depressive symptoms than NGT (1612; 87.5%) women [21.3% (48) vs 15.1% (239), odds ratio (OR) 1.52, 95% confidence interval (CI) (1.08-2.16), P = 0.017]. Compared to GDM women without depressive symptoms, depressed GDM women attended less often the postpartum OGTT [68.7% (33) vs 87.6% (155), P = 0.002], remained more often depressed [37.1% (13) vs 12.4% (19), P < 0.001], and had lower SF-36 scores postpartum. There were no significant differences in pregnancy outcomes between both groups. Rates of labor inductions were significantly higher in the NGT group with depressive symptoms compared to the nondepressed NGT group [31.7% (75) vs 24.7% (330), adjusted OR (aOR) 1.40, 95% CI (1.01-1.93), P = 0.041]. NGT women with depressive symptoms had lower SF-36 scores (P < 0.001) postpartum compared to nondepressed NGT women. Conclusions Women with antenatal symptoms of depression develop more often GDM. GDM women with depressive symptoms remain more often depressed postpartum with lower quality of life. NGT women with depressive symptoms have higher rates of labor inductions and lower quality of life postpartum compared to nondepressed NGT women.

This study determines if a modified two-step screening strategy with a glucose challenge test (GCT) ≥ 7.2 mmol/L and clinical risk factors improves the diagnostic accuracy for gestational diabetes mellitus (GDM), based on 2013 WHO criteria, while limiting the number of oral glucose tolerance tests (OGTT). This was a prospective multicentric cohort study with 1811 participants receiving both GCT and 75 g OGTT in pregnancy. Participants and health care providers were blinded for GCT. Characteristics were analyzed across four glucose tolerance groups: abnormal (≥7.2 mmol/L), GCT GDM (n = 165), normal GCT GDM (n = 63), abnormal GCT normal glucose tolerant (NGT) (n = 472); normal GCT NGT (n = 1113). Compared to normal GCT NGT women, normal GCT GDM women had increased rates of obesity (23.8% vs. 10.5%, p < 0.001), ethnic minority background (19.3% vs. 8.2%, p < 0.001) and a history of GDM (13.8% vs. 4.6%, p = 0.03). By combined screening of GCT ≥ 7.2 mmol/L with these risk factors, sensitivity increased to respectively, 74.1–78.1% using one risk factor, and to 82.9% using any of these risk factors with a specificity of 57.5%. By using a modified two-step screening strategy, the number of women needing both a GCT and OGTT would be reduced to 25.5%, and 52.6% of all OGTTs could be avoided, compared to a universal one-step approach.

Gestational diabetes mellitus (GDM) is a frequent medical complication during pregnancy. Screening and diagnostic practices for GDM are inconsistent across the world. This narrative review includes data from 87 observational studies and randomized controlled trials (RCTs), and aims to give an overview of the current evidence on screening strategies and diagnostic criteria for GDM. Screening in early pregnancy remains controversial and studies show conflicting results on the benefit of screening and treatment of GDM in early pregnancy. Implementing the one-step “International Association of Diabetes and Pregnancy Study Groups” (IADPSG) screening strategy at 24– 28 weeks often leads to a substantial increase in the prevalence of GDM, without conclusive evidence regarding the benefits on pregnancy outcomes compared to a two-step screening strategy with a glucose challenge test (GCT). In addition, RCTs are needed to investigate the impact of treatment of GDM diagnosed with IADPSG criteria on long-term maternal and childhood outcomes. Selective screening using a risk-factor-based approach could be helpful in simplifying the screening algorithm but carries the risk of missing significant proportions of GDM cases. A two-step screening method with a 50g GCT and subsequently a 75g oral glucose tolerance test (OGTT) with IADPSG could be an alternative to reduce the need for an OGTT. However, to have an acceptable sensitivity to screen for GDM with the IADPSG criteria, the threshold of the GCT should be lowered from 7.8 to 7.2 mmol/L. A pragmatic approach to screen for GDM can be implemented during the COVID-19 pandemic, using fasting plasma glucose (FPG), HbA1c or even random plasma glucose (RPG) to reduce the number of OGTTs needed. However, usual guidelines and care should be resumed as soon as the COVID pandemic is controlled.

Aim: To determine the association between thyroid function and the risk of developing gestational diabetes mellitus (GDM) and adverse pregnancy outcomes. Methods: This case–control study was a sub-analysis of the BEDIP-N study, in which 199 GDM women were matched for age and body mass index with 398 controls. Thyroid-stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), and thyroid peroxidase (TPO) antibodies were measured at 6–14 weeks and 26–28 weeks during pregnancy. TSH and fT4 were also measured in early postpartum in GDM women. Results: The fT3-to-fT4 ratio at 26–28 weeks was positively associated with GDM risk with an adjusted odds ratio (aOR for smoking, education, parity, ethnicity, gestational weight gain, and (family) history of diabetes or GDM) of 2.12 (95% CI 1.07; 4.23), comparing the highest with the lowest tertile. Higher fT3 levels and a higher fT3-to-fT4 ratio were associated with a less favorable metabolic profile with higher BMI and more insulin resistance during pregnancy and postpartum. Women in the upper fT3 tertile and the upper fT3-to-fT4 ratio had a higher rate of preeclampsia [4.6% (10) vs. 1.0% (2), p = 0.040, and 4.4% (9) vs. 0.5% (1), p = 0.020], gestational hypertension [8.3% (18) vs. 3.1% (6), p = 0.034 and 8.9% (18) vs. 2.0% (4), p = 0.003], and caesarean sections [29.4% (63) vs. 16.1% (31), p = 0.002 and 32.2% (65) vs. 12.7% (25), p < 0.001]. Conclusion: A higher fT3-to-fT4 ratio late into pregnancy was associated with GDM, adverse pregnancy outcomes, and an adverse metabolic profile in early postpartum.