Increased Incidence in Gestational Diabetes Mellitus by Race and Ethnicity during the COVID-19 Pandemic: Results from a Large Medical Center in the United States

Abstract

Background: Gestational diabetes mellitus (GDM) is a common pregnancy complication, and its risk increases in females exposed to stressful events. The COVID-19 pandemic has affected the healthcare system and individuals’ behaviors, but its impact on GDM risk remains unclear. We aimed to investigate the influence of the pandemic on GDM risk in the United States (US), overall and by race/ethnicity. Methods: This retrospective cohort study included pregnancies in an academic medical system in Los Angeles, California. We divided 8,518 pregnancies into the pre-COVID cohort (4,507 delivered between 9/1/2018 and 2/29/2020; 18 months) and the intra-COVID cohort (4,011 delivered between 3/1/2020 and 8/31/2021; 18 months). We ascertained GDM cases using the ICD-10 codes, calculated the age-standardized GDM incidences, and estimated the risk ratios (RR) of GDM (intra-COVID vs. pre-COVID) using Poisson regressions. Results: The age-standardized GDM incidence was 8.49% in the pre-COVID and 10.02% in the intra-COVID cohorts. The GDM risk was 17% higher in the intra-COVID cohort than in the pre-COVID cohort (RR=1.17; 95% CI: 1.02, 1.35) after adjusting for race/ethnicity, maternal age, nulliparity, marital status, pre-pregnancy body mass index, gestational weight gain, and utilization days of prenatal care. When stratified by race/ethnicity, the GDM risk was higher in non-Hispanic Whites (RR=1.34; 95% CI: 1.03, 1.74), Hispanics (RR=1.26; 95% CI: 1.00, 1.59), and potentially in non-Hispanic Blacks (RR=1.32; 95% CI: 0.63, 2.76), but not in Asians (RR=0.99; 95% CI: 0.75, 1.30). Conclusion: GDM incidences increased during the COVID-19 pandemic in a large US city, especially among non-Hispanic Whites, Hispanics, and non-Hispanic Blacks.