Gestational diabetes

Type 2 diabetes (T2D) and hypertension are the commonest comorbidities in patients with SARS-CoV-2, and Bornstein et al (2020) draw attention to emerging evidence for a direct metabolic and endocrine link to the disease process.

Given this context, it is perhaps timely to reconsider gestational diabetes mellitus (GDM), defined as glucose intolerance that is first diagnosed in pregnancy; increases the risk of complications for both mother and baby during pregnancy; and has a European prevalence of 5.4%, ranging from 3.8%–7.8% (Eades et al, 2017).

Further, Van-de-l'Isle et al (2020) note that GDM complicates around one in 16 pregnancies in the UK, citing evidence that GDM treatment improves perinatal outcomes: women with untreated GDM have a four-fold risk of having a baby large for gestational age or macrosomia (birthweight >4 000 g) compared with those treated for GDM. Such observations strengthen the need for improved identification of GDM, and Van-de-l'Isle et al (2020) investigated the differences in detection rate for GDM between that recommended by the National Institute for Health and Clinical Excellence (NICE) and the testing considered appropriate during the COVID-19 pandemic by the Royal College of Obstetricians and Gynaecologists (RCOG). Following RCOG guidance, the overall rate of women identified with GDM fell from 7.7%–4.2%, and of 230 women who tested negative according to the RCOG criteria but who subsequently had an oral glucose tolerance test, 20.4% were diagnosed with GDM according to the NICE criteria. With RCOG COVID-19 GDM screening failing to detect 47 of 82 (57%) women subsequently identified as gestational diabetics, Van-de-l'Isle et al (2020) suggest that RCOG GDM screening ‘cannot be recommended for general use.’