A new study published in Pediatrics on March 14 has found no link between COVID-19 vaccination in early pregnancy and an increased risk of major structural birth defects. The research provides reassurance to expectant mothers and healthcare providers that receiving the vaccine during the first 20 weeks of pregnancy does not pose additional risks to fetal development.

Conducted by Dr. Stacey L. Rowe and colleagues at the University of San Francisco, the study analyzed data from a claims-based cohort of pregnancies that resulted in live births. The research focused on individuals with an estimated last menstrual period between August 15, 2021, and December 24, 2021. The study compared the prevalence of major birth defects among vaccinated and unvaccinated individuals, as well as differences between the Moderna and Pfizer-BioNTech vaccines.

Among the 78,052 pregnancies reviewed, researchers identified 1,248 cases of major structural birth defects—1,049 in unvaccinated individuals and 199 in vaccinated individuals. The rates were nearly identical, at 160.6 and 156.4 per 10,000 live births, respectively, showing no significant difference in birth defect prevalence based on vaccination status. The findings remained consistent across various factors, including insurance provider, COVID-19 infection during pregnancy, and administration of other maternal vaccines. Additionally, no difference in birth defect prevalence was observed between those who received the Moderna or Pfizer-BioNTech vaccines.

“These findings align with previous studies and offer further reassurance to pregnant individuals and healthcare providers considering COVID-19 vaccination in early pregnancy,” the study authors noted.

The study contributes to growing evidence supporting the safety of COVID-19 vaccination during pregnancy. However, two of the study’s authors disclosed ties to pharmaceutical companies, including Moderna and Pfizer.