Pregnant women infected with the coronavirus are at significantly higher risk for adverse complications, including preterm birth, according to a University of California San Francisco analysis of all documented births in the state between July 2020 and January 2021.
In the largest study of its kind, researchers found the risk of very preterm birth, which occurs at less than 32 weeks of gestation, was 60% higher for people infected with the coronavirus during their pregnancy. The risk of giving birth at less than 37 weeks — which is any preterm birth — was 40% higher.
“The risk is very real,” said Dr. Laura Jelliffe-Pawlowski, senior author of the report and professor of epidemiology and biostatistics in the UCSF School of Medicine. “It means you and your baby may start your relationship in the world by being in the hospital much longer than expected.”
Of the 240,157 recorded births analyzed, nearly 9,000, or 3.7%, had a COVID-19 diagnosis, based on testing, during pregnancy. The preterm birth rate among those infected was 11.8% compared with 8.7% among those who were not infected, substantiating the devastating impact of the pandemic on pregnant women highlighted by previous studies.
“I don't think the findings were necessarily surprising, but they confirm that infection in pregnancy can lead to these adverse outcomes,” said Dr. Deborah Karasek, lead author of the report and assistant professor in the department of obstetrics, gynecology and reproductive sciences.
For pregnant women with comorbidities -- such as hypertension, diabetes and/or obesity -- and COVID-19, the risk of very preterm birth rose by 160% and preterm birth by 100%.
The study also found that existing disparities in COVID-19 rates for communities of color carried over to pregnancy outcomes. The 47% of pregnant women in the study who were Latina represented 72% of the people with COVID-19 diagnoses.
“We have to be nimble and be able to talk about the multiple ways we can protect women,” said Jelliffe-Pawlowski. “We have to talk about work policies that allow women to stay home longer, avoid contact with others, work in safe places.”
The researchers hope the data will help patients and doctors have conversations about vaccinations and pregnancy, especially at a time when the delta variant is spreading as rapidly as social media misinformation around the impacts of vaccines and fertility.
They hope also the data on risk of preterm birth could inform the public health message on coronavirus vaccination. The Centers for Disease Control and Prevention cites experts saying the vaccines are unlikely to pose a risk for pregnant people, but notes, too, that there is limited data on vaccine safety for them. Pregnant women were not included in studies that led to the government’s emergency authorization of the vaccines.
“Hopefully, the evidence is enough,” said Karasek. “At the same time, we need to meet people where they are. This is not a one-time conversation. This is an ongoing conversation.
First published in SF Chronicle