Effects of COVID-19 Infection on the Oral Glucose Tolerance Test Results in Pregnancy

The aim of this study was to evaluate the results of a 75 g oral glucose tolerance test (OGTT) performed in the second trimester of pregnancy, the prevalence of gestational diabetes mellitus (GDM), and perinatal outcomes in pregnant women with a history of coronavirus disease 2019 (COVID-19) infection and to examine the effect of COVID-19 infection history on OGTT results and GDM prevalence.

We retrospectively analyzed the data of 463 patients who visited the Gynecology and Obstetrics Department of Kayseri City Hospital between March 2020 and January 2023 and were administered a 75-g OGTT in the second trimester of their pregnancy. Accordingly, we traced COVID-19 history, OGTT results, GDM prevalence, and newborn outcomes among the patients.

OGTT glucose values were higher in the study group with a history of COVID-19 infection, but there was no significant difference between the groups. GDM developed in 13 (23.2%) pregnant women in the group with a history of COVID-19 infection and 88 (21.6%) pregnant women in the control group without a history of COVID-19 (p: 0.348). In addition, in pregnant women diagnosed with GDM, insulin requirement was 8.9% in the COVID-19 (+) group and 5.1% in the COVID-19 (-) group, and the results were not statistically significant (p: 0.178). There was no significant difference in neonatal outcomes between the groups.

In our study, we found that glucose values were higher and the prevalence of GDM was higher in pregnant women with a history of COVID-19 infection before the OGTT. It is necessary to be more careful about issues such as blood glucose regulation and GDM risk in pregnancy follow-up after infections such as COVID-19, which may have widespread systemic inflammatory effects, and patients should be informed in detail for pregnancy follow-up.