Gestational diabetes is associated with SARS-CoV-2 infection during pregnancy: A case-control study

Introduction Diabetes mellitus has been identified as a risk factor for a severe course of COVID-19 in pregnant women. In addition, it has been suggested that SARS-CoV-2 infection may trigger the development of diabetes mellitus through direct destruction of the pancreatic Langerhans cells. Until now, little data regarding an association between gestational diabetes (GDM) and risk of SARS-CoV-2 infection during pregnancy is available. The aim of our study was to investigate this possible association in our population using a case-control model.

Material and methods We included 85 pregnant women with symptomatic or asymptomatic SARS-CoV-2 infection in our study, who were managed at our institution starting with May 2020 to date. We matched these cases 1:2 with a cohort of women managed at our hospital between before 30.10.2019 based on parity, BMI and ethnicity. Screening for gestational diabetes by a 75 mg oral glucose tolerance test (OGTT) was performed at 26 weeks“ gestation in all women. Clinical data on pregnancy outcomes were collected.

Results Of the 85 women included in the case group, OGTT was available in 75 cases. Diagnosis of gestational diabetes was made in 23 women in the case group (30.66%), vs. 20 in the control group (13.42%). This difference was statistically highly significant (p 0.0036 through two-sided Fisher"s exact test, where p<0.05 was considered as significant) . Mean age was 30.42 years old (SD±4.65) in the case group and 30.39 years old (SD±4.77) in the cohort group. Mean BMI was 26.10 (SD±5.13) in the case and 25.67 in the control group (SD±5.10) When classifying patients into not-overweight (BMI<25 kg/m2) vs. overweight (BMI≥25 kg/m2), 60.86% of the women with GDM in the case group were overweight vs. 80% in the control group. This difference was statistically significant. According to the WHO classification of the severity of COVID-19, most women presented with mild or moderate course of the disease. In four women, hospitalization was necessary because of severe COVID-19 infection. Of these, two (50%) suffered from GDM.

Discussion The main finding in our study is a significantly higher rate of GDM among women with SARS-CoV-2 infection during pregnancy, when compared to a control group. We speculate that GDM increases the risk of SARS-CoV-2 infection in pregnant women. On the other hand, the infection might increase the risk of developing GDM. Interestingly, in the women who developed GDM in the control group, significantly more patients with overweight were found than in the case group (80 vs. 60.86%). It remains open, if SARS-CoV-2 acted as an additional ‘promoter’ for developing GDM in these women. To our knowledge, this is the first study showing a possible correlation between GDM and SARS-CoV-2 infection. Further studies are needed to confirm this association and the potential mechanism behind it.

Fig. 1 Significantly higher proportion of GDM in the SARS-CoV-2 group.

Publication History

Article published online:
26 November 2021