COVID-19 Severity among Women of Reproductive Age with Symptomatic Laboratory-Confirmed SARS-CoV-2 by Pregnancy Status – United States, Jan 1, 2020 – Sep 30, 2021

Importance: Pregnant people are at increased risk for severe COVID-19 compared with nonpregnant people. Limited information is available on the severity of COVID-19 attributable to the Delta variant, the predominant variant in the United States as of late June 2021, among pregnant persons.Objective: To assess risk for severe COVID-19 by pregnancy status and time period relative to Delta variant predominance. Design: Using a cross-sectional design, we describe characteristics of symptomatic women of reproductive age (WRA) with COVID-19 and calculate adjusted risk ratios for severe disease comparing pregnant with nonpregnant WRA during the pre-Delta period (January 1, 2020 – June 26, 2021) and the Delta period (June 27, 2021 – September 30, 2021). Additionally, we calculate adjusted risk ratios for severe disease comparing the Delta period with the pre-Delta period for pregnant and nonpregnant WRA.Setting: Reports of COVID-19 in the United States occurring from January 1, 2020 ─ September 30, 2021, submitted to the CDC.Participants: Pregnant and nonpregnant women aged 15-44 years.Exposure(s): Laboratory-confirmed, symptomatic SARS-CoV-2 infection.Main Outcome(s): Severe disease: (intensive care unit [ICU] admission, receipt of invasive ventilation or extracorporeal membrane oxygenation [ECMO], and death).Results: Among 1,856,428 cases of symptomatic COVID-19 in WRA, the risk for severe disease was increased among pregnant compared with nonpregnant WRA during the pre-Delta and Delta periods. Compared with the pre-Delta period, the risk of ICU admission during the Delta period was 66% higher (adjusted risk ratio [aRR] 1.66, 95% CI: 1.34-2.06) for pregnant WRA and 23% higher (aRR 1.23, 95% CI: 1.12-1.35) for nonpregnant WRA. The risk of invasive ventilation or ECMO was higher for pregnant and nonpregnant WRA in the Delta period. During the Delta period, the risk of death was 3.40 (95% CI: 2.36-4.91) times the risk in the pre-Delta period among pregnant WRA and 1.96 (95% CI: 1.75-2.18) among nonpregnant WRA. Conclusions and Relevance: The overall risk for severe COVID-19 among WRA remains low; however, symptomatic pregnant WRA remain at increased risk for severe outcomes compared with symptomatic nonpregnant WRA during Delta variant predominance. Compared with the pre-Delta period, pregnant and nonpregnant WRA are at increased risk for severe COVID-19 in the Delta period.