First-trimester COVID-19 vaccine does not increase risk for birth defects

by Lori Solomon

First-trimester mRNA COVID-19 vaccine exposure is not associated with an increased risk for selected major structural birth defects, according to a study published online July 1 in JAMA Pediatrics.

Elyse O. Kharbanda, M.D., M.P.H., from HealthPartners Institute in Minneapolis, and colleagues assessed whether receipt of an mRNA COVID-19 vaccine during the first trimester is associated with an increased risk for selected major structural birth defects among live-born infants. The analysis included 42,156 singleton pregnancies with live birth in the Vaccine Safety Datalink from March 5, 2021, to Jan. 25, 2022, from eight health systems in California, Oregon, Washington, Colorado, Minnesota, and Wisconsin.

The researchers found that selected major structural birth defects occurred in 1.48% of infants after first-trimester mRNA COVID-19 vaccination and in 1.41% of infants without first-trimester vaccine exposure (adjusted prevalence ratio, 1.02; 95% confidence interval, 0.78 to 1.33). Similarly, there were no significant differences between infants exposed or not exposed to vaccination during the first trimester of pregnancy when examining major structural birth defect outcomes grouped by organ system.

“In this multisite cohort study, among live-born infants, first-trimester mRNA COVID-19 vaccine exposure was not associated with an increased risk for selected major structural birth defects,” the authors write. “These findings support the safety of maternal COVID-19 vaccination in the first trimester.”

Several authors disclosed ties to industry.