Higher severe acute respiratory syndrome coronavirus 2 infection rate in pregnant patients

Background During the early months of the coronavirus disease of 2019 (COVID-19) pandemic, risks to pregnant women of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were uncertain. Pregnant patients can serve as a model for the success of the clinical and public health response during public health emergencies as they are typically in frequent contact with the medical system. Population-based estimates of SARS-CoV-2 infections in pregnancy are unknown due to incomplete ascertainment of pregnancy status or inclusion of only single centers or hospitalized cases. Whether pregnant women were protected by the public health response or through their interactions with obstetrical providers in the early pandemic is poorly understood. Objective(s) To estimate the SARS-CoV-2 infection rate in pregnancy and examine disparities by race/ethnicity and English-language proficiency in Washington State. Study design Pregnant patients with a polymerase chain reaction (PCR)-confirmed severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection diagnosed between March 1-June 30, 2020 were identified within 35 hospitals/clinic systems capturing 61% of annual deliveries in Washington State. Infection rates in pregnancy were estimated overall and by Washington State Accountable Community of Health (ACH) region and cross-sectionally compared to SARS-CoV-2 infection rates in similarly aged adults in Washington State. Race/ethnicity and language used for medical care among the pregnant patients were compared to recent data from Washington State. Results A total of 240 pregnant patients with SARS-CoV-2 infections were identified during the study period with 70.7% from minority racial and ethnic groups. The principal findings in our study are: 1) The SARS-CoV-2 infection rate in pregnancy was 13.9/1,000 deliveries (95% confidence interval [CI], 8.3-23.2) compared to 7.3/1,000 (95%CI 7.2-7.4) in 20-39 year old adults in Washington State (Rate Ratio [RR] 1.7, 95%CI 1.3-2.3), 2) the SARS-CoV-2 infection rate reduced to 11.3/1000 (95%CI 6.3-20.3) when excluding 45 cases of SARS-CoV-2 detected through asymptomatic screening (RR 1.3, 95%CI 0.96-1.9), 3) the proportion of SARS-CoV-2 cases in pregnancy among most non-white racial/ethnic groups was 2-4 fold higher than the race and ethnicity distribution of women in Washington State who delivered live births in 2018, and 5) the proportion of SARS-CoV-2 infected pregnant patients receiving medical care in a non-English language was higher than estimates of limited English proficiency in Washington State (30.4% versus 7.6%). Conclusions The SARS-CoV-2 infection rate in pregnant people was 70% higher than similarly aged adults in Washington State, which could not be completely explained by universal screening at delivery. Pregnant patients from nearly all racial/ethnic minority groups and patients receiving medical care in a non-English language were overrepresented. Pregnant women were not protected from COVID-19 in the early months of the pandemic with the greatest burden of infections occurring in nearly all racial/ethnic minority groups. This data coupled with a broader recognition that pregnancy is a risk factor for severe illness and maternal mortality strongly suggests that pregnant people should be broadly prioritized for COVID-19 vaccine allocation in the U.S. similar to some states.