Pregnant women face similar risk for SARS-CoV-2 infection as general population
Data from before the delta variant emerged indicated that the incidence of SARS-CoV-2 infection among pregnant women was 1% per week, which is similar to that of the general population of U.S. adults, according to a recent study.
The CDC has previously reported reassuring data on the safety of receiving a COVID-19 vaccine during pregnancy and has encouraged pregnant women — who face a higher risk for severe outcomes — to get vaccinated.
However, “data on community incidence of SARS-CoV-2 infection and risk factors for infection among pregnant individuals are needed to inform infection prevention counseling and guidance,” Fatimah S. Dawood, MD, a medical epidemiologist in the CDC’s Influenza Division, and colleagues wrote in the new study.
“This study was designed to estimate incidence rates of SARS-CoV-2 infection during pregnancy and to describe the clinical characteristics of SARS-CoV-2 infections during pregnancy,” Dawood told Healio. “Data that quantify the risk of becoming infected with SARS-CoV-2 during pregnancy can inform counseling for pregnant individuals about the value of infection prevention practices, including COVID-19 vaccination.”
Dawood and colleagues prospectively followed a cohort of pregnant people from August 2020 through March 2021 at three different U.S. sites. According to the study, the three primary outcomes were incidence rates of any SARS-CoV-2 infection, symptomatic infection, and asymptomatic infection during pregnancy during periods of SARS-CoV-2 circulation.
The researchers had the study participants self-collect weekly midturbinate nasal swabs for SARS-CoV-2 testing, complete weekly illness symptom questionnaires, and submit additional swabs with COVID-19–like symptoms.
Among the 1,098 pregnant women included in the study, 9% (99/1,098) tested positive for SARS-CoV-2 during the study. Dawood and colleagues calculated the population-weighted incidence rates of SARS-CoV-2 infection as 10 per 1,000 (95% CI, 5.7-14.3) person-weeks for any infection, 5.7 per 1,000 (95% CI, 1.7-9.7) for symptomatic infections, and 3.5 per 1,000 (95% CI, 0-7.1) for asymptomatic infections.
The median duration of symptoms was 10 days, with the most common symptoms being nasal congestion (72%), cough (64%), headache (59%) and change in taste or smell (54%).
Dawood says the findings suggest that pregnant women “have a similar risk” for becoming infected with SARS-CoV-2 compared with the general adult population. The data were collected before the emergence of the delta variant, Dawood said.
“Individuals who are pregnant during periods of SARS-CoV-2 circulation in their communities are at substantial risk for becoming infected with SARS-CoV-2,” Dawood said. “These findings, coupled with data from other studies showing that pregnancy increases the risk of severe illness with COVID-19, underscore the importance of SARS-CoV-2 prevention measures during pregnancy, such as mask-wearing and getting a COVID-19 vaccine.”