(CNN) – A new study suggests the COVID-19 vaccines from Pfizer and Moderna do not appear to pose a serious risk during pregnancy.
Researchers reviewed data of more than 35,000 pregnant women from December through February.
The information on pregnancy outcomes and complications came from the Centers for Disease Control and Prevention’s V-safe smartphone-based surveillance system.
The study also looked at pregnancy-related adverse events reported to the CDC’s vaccine adverse event reporting system (VAERS).
Researchers found the most common side effect from the vaccine was pain at the injection site, which appeared more frequently in vaccine recipients who were pregnant.
Other side effects like headache, muscle aches, chills and fever were reported less frequently.
Researchers say more long-term studies are needed.
The study appeared in Wednesday’s New England Journal of Medicine.