New findings published in JAMA Pediatrics show COVID-19 vaccination during the first trimester of pregnancy is not associated with an increased risk for selected birth defects. The study was designed and led by HealthPartners Institute researchers and adds to a growing body of research of the safety of vaccines administered during pregnancy.

Several types of major structural birth defects were monitored, including cardiac, gastrointestinal and musculoskeletal. These defects are rare events that occur while the fetus is developing during early pregnancy.

Researchers evaluated 42,156 pregnancies resulting in a live birth. Race and ethnicity data were included to account for variability with COVID-19 uptake and birth outcome. Selected major structural birth defects were found in 1.48% of infants born after a first trimester mRNA COVID-19 vaccination exposure and 1.41% of infants without an exposure.

“COVID-19 infection during pregnancy can increase risk of complications, but people who are pregnant are often hesitant to be vaccinated because of concerns over safety,” said Dr. Elyse Kharbanda, senior research investigator, executive director of research at HealthPartners Institute and lead author of the study. “This study should increase confidence regarding vaccination during pregnancy, including during the first trimester.”

The study was a multisite observational cohort that included data from HealthPartners and seven other health systems in the Vaccine Safety Datalink (VSD). The VSD is a research network funded by the Centers for Disease Control and Prevention that includes a diverse population and conducts post-marketing surveillance of vaccines licensed and used in the United States.