Possible Causal Relationship Between COVID-19 and Gestational Diabetes Onset

Detail of pregnant woman’s belly, and she holding a glucose meter.
Researchers assessed the prevalence of gestational diabetes among women with COVID-19 infection who were pregnant and the risk factors associated with severe disease.

A possible causal relationship was observed in which COVID-19 infection increased the risk for gestational diabetes mellitus (GDM) and GDM increased the risk for COVID-19 infection, according to results of a study published in Diabetes & Metabolism.

This case-control study reviewed records of 75 women who received care for COVID-19 infection during pregnancy at the Hospital of Bern in Switzerland between 2020 and 2021. Each patient was matched in a 1:2 fashion against an historical cohort (controls) of women (n=149) who were pregnant and delivered between 2016 and 2019.

Among patients in the COVID-19 and control groups, the mean age was 30.76 and 30.62 years, BMI was 26.27 and 25.91 kg/m2, 80% and 80% were White, and 17.3% and 7.6% delivered preterm (P =.04), respectively.

Among patients with COVID-19 infection during pregnancy, 14.66%, 25.33%, and 49.33% were diagnosed in the first, second, and third trimesters, respectively. Of these patients, most (89.33%) had asymptomatic, mild, or moderate infection, and few (n=4) had severe disease requiring transfer to an intensive care unit and/or mechanical ventilation. No deaths were observed.

The researchers found that GDM occurred more frequently among patients in the COVID-19 group vs those in the control group (34.7% vs 16.1%; P =.002). Among patients in the COVID-19 group, 35.7% were diagnosed with GDM after recovering from the infection.

Among 9 patients with COVID-19 infection who were hospitalized, 4 required ICU transfer. Of these 4 patients, 2 had GDM. Using multivariate logistic regression, the researchers found that positive COVID-19 infection (odds ratio [OR], 2.79; 95% CI, 1.42-5.47; P =.003) and BMI (OR, 1.12; 95% CI, 1.05-1.19; P =.001) significantly increased the risk for GDM.

After the researchers performed a regression analysis for factors associated with inpatient vs outpatient COVID-19 management, no significant differences were observed for GDM (OR, 1.14; 95% CI, 0.22-5.80; P =.88), time of COVID-19 infection onset (OR, 1.08; 95% CI, 0.98-1.20; P =.12), or BMI (OR, 1.07; 95% CI, 0.91-1.25; P =.41).

This study was limited by its small sample size, and patients were not matched on the basis of potential comorbidities or socioeconomic status.

These data underscore the importance of vaccination and taking precautions to prevent COVID-19 infection during pregnancy. These results also suggest a “possible causal relationship between COVID-19 [infection] and onset of GDM,” the researchers concluded.


Radan A-P, Fluir M-M, Nirgianakis K, et al. Gestational diabetes is associated with SARS-CoV-2 infection during pregnancy: A case-control study. Diabetes Metab. 2022;101351. doi:10.1016/j.diabet.2022.101351