Messenger RNA vaccines for COVID-19, such as those produced by Moderna and Pfizer, showed no obvious safety concerns for pregnant women, according to a preliminary report published Wednesday in the New England Journal of Medicine.
Researchers looked at real-world data from more than 35,000 pregnant women who received an mRNA vaccine between Dec. 14, 2020, and Feb. 28 and found there were no major health-related issues for the mothers or the newborns, according to the study. Pfizer and Moderna are the only two mRNA COVID-19 vaccines currently granted emergency use authorization by the Food and Drug Administration.
The study utilized data from several federal health sources, including the U.S. Centers for Disease Control and Prevention's V-safe After Vaccination Health Checker, V-Safe pregnancy registry and the federal government's Vaccine Adverse Event Reporting System.
After receiving the vaccine, pregnant women reported pain at the injection site more frequently, and headaches, chills and fevers less frequently than nonpregnant women, researchers said.
There were 721 women who were in the V-Safe pregnancy registry who had live births during the study period, according to the paper. There were no reported neonatal deaths, researchers said.
While some women experienced miscarriage, premature birth and babies that were small, the frequency of these events was similar to studies before the pandemic, the study said.
The CDC says getting vaccinated is a personal choice for pregnant women and they should discuss the risks and benefits with their doctors.
Pfizer is conducting a clinical trial in pregnant women, but the results won't be available until later this year.
Dr. Sara Yumeen, a preliminary-year internal medicine resident at Hartford Healthcare St. Vincent's Medical Center and contributor to the ABC News Medical Unit, contributed to this report.