Risk of Severe Coronavirus Disease 2019 (COVID-19) in Pregnant and Postpartum Individuals After the Pandemic Emergency.

Abstract

To evaluate the risks of severe coronavirus disease 2019 (COVID-19)-related outcomes among pregnant and postpartum individuals and nonpregnant women during the Delta variant period and after the pandemic emergency ended in the United States. We conducted a retrospective cohort study of 18- to 49-year-old women identified in a national U.S. commercial insurance claims database during the Delta variant (July 1-December 20, 2021) and postemergency periods (May 11, 2023-September 10, 2024). Pregnant and postpartum individuals unvaccinated for COVID-19 during the year before follow-up were propensity score-matched to four nonpregnant women. Primary outcomes were laboratory-confirmed or clinically diagnosed COVID-19 with subsequent COVID-19 hospitalization, pneumonia hospitalization, or a severe composite COVID-19 hospitalization such as acute respiratory failure, intensive care unit admission, acute respiratory distress syndrome, or respiratory support. Among the individuals followed during the Delta variant (1,109,384) and postemergency (878,003) periods, hospitalization rates with COVID-19 were substantially higher among pregnant individuals than among postpartum individuals or nonpregnant women. In propensity score-matched analyses, the risks of all primary outcomes were elevated for individuals who were pregnant during the Delta period, compared with matched nonpregnant women. Although absolute risks of severe COVID-19 outcomes were lower during the postemergency period, the relative risks (RRs) of COVID-19 hospitalization (RR 4.09; 95% CI, 3.65-4.59) and pneumonia hospitalization (RR 2.78; 95% CI, 1.38-4.81) during pregnancy remained elevated. The RR for severe composite COVID-19 hospitalization (RR 2.17; 95% CI, 0.35-6.67) was imprecise, reflecting substantial uncertainty. Risks for severe COVID-19-related outcomes were also elevated postpartum. Sensitivity analyses reinforced these findings. Higher risks of severe COVID-19-related outcomes among pregnant and postpartum individuals have persisted since the resolution of the pandemic emergency.