Changes in Rates of Adverse Pregnancy Outcomes During the COVID-19 Pandemic: A Cross-Sectional Study in the United States, 2019-2020

Background: The population-level impact of the COVID-19 pandemic on pregnancy and delivery outcomes is not well understood. Our objective was to assess whether pregnancies that ended during the pandemic had different risks of selected adverse outcomes compared to the previous year.Methods: Data from a cross-sectional study of delivery hospitalizations occurring during April-December of 2019 and 2020 in the Premier Healthcare Database were analyzed. Adjusted prevalence ratios (aPR) and 95% confidence intervals (CI) were estimated using Poisson regression with robust standard errors.Findings: We identified 663,620 deliveries occurring April-December of 2019 and 614,093 deliveries occurring April-December of 2020. We observed an increase in in-hospital death from 2019 to 2020 (n=33; 5 per 100,000 vs. n=53; 9 per 100,000, aPR: 1·68, CI: 1·09, 2·59), which was no longer statistically significant after excluding deliveries with a COVID-19 diagnosis (aPR: 1·25, CI: 0·78, 2·00). Intensive care unit admission decreased from 2019 to 2020 (1·7% vs· 1·5%, aPR: 0·90, CI: 0·87, 0·92). Preterm birth decreased from 2019 to 2020 (9·2% vs· 9·1%, aPR: 0·96, CI: 0·95, 0·97). There was no difference in the prevalence of most other pregnancy and delivery outcomes examined.Interpretation: In 2020 compared to 2019, in-hospital deaths among pregnant women increased and there was a small decrease in prevalence of preterm births. The full impact of the COVID-19 pandemic on maternal and pregnancy outcomes remains to be understood. It appears that most outcomes investigated experienced minimal change from 2019 to 2020.Funding Information: No funding was secured for this study.Declaration of Interests: The authors do not have any potential conflicts of interest to declare.Ethics Approval Statement: This activity was reviewed by the Centers for Disease Control and Prevention (CDC) and was determined to meet the requirements of public health surveillance. It was conducted consistent with applicable federal law and CDC policy (see, 45 C.F.R. part 46, 21 C.F.R. part 56; 42 U.S.C. §241(d); 5 U.S.C. §552a; 44 U.S.C. §3501 et seq.).