COVID-19 vaccines are unlikely to pose a risk for pregnant women, however only limited data on the safety of such vaccines in pregnant individuals remains available, according to updated guidance from the Centers for Disease Control and Prevention.
The CDC said last month it expects data from trials testing vaccines later this summer, according to a top official, and the agency has already received "reassuring data" on doses given to women in their third trimester.
In late April, the CDC announced it was recommending shots for pregnant women after preliminary data showed that Pfizer's and Moderna's vaccines were safe for women as well as their babies. The guidance indicated studies found "no obvious safety signals" surrounding vaccination in pregnant women.
The researchers looked at data from 35,691 women, who ranged in age from 16 to 54, in a peer-reviewed study published in The New England Journal of Medicine. Data used in the research was self-reported using the "v-safe after vaccination health checker," researchers noted.
Although the vaccines haven't been officially cleared for use in pregnant women, the CDC's principal deputy director said pregnant women should have access to the vaccines because they can get sicker from COVID-19 than other people.
"Women who are pregnant and get Covid have worse experiences with the infection than do non-pregnant women," CDC Principal Deputy Director Dr. Anne Schuchat said at a U.S. Senate hearing in mid-May. "More time in the intensive care unit, more risk of severe outcomes including those rare deaths..."
Schuchat also said new data shows vaccinated mothers can transfer their COVID antibodies to their babies while breastfeeding.
Dr. Soumya Swaminathan, chief scientist with the World Health Organization, explained contracting COVID increases the risk for delivering a baby prematurely.
"So, in situations where there is a lot of COVID transmission in the country and a woman is exposed to it, or if she's in a profession like a health care worker or a frontline worker where she's at especially high risk of acquiring the infection, the benefits of getting the vaccine definitely outweigh the risks," the doctor explained.
The American College of Obstetricians and Gynecologists recommends that COVID-19 vaccines "should not be withheld from pregnant individuals who meet criteria for vaccination based on ACIP-recommended priority groups."
"In the interest of patient autonomy, ACOG recommends that pregnant individuals be free to make their own decision regarding COVID-19 vaccination," the group states.
The University of Chicago Medicine agreed with the CDC recommendations, saying pregnant women should be given the choice.
"This is an individualized decision and pregnant/breastfeeding people should be offered the choice to get vaccinated," the health system previously said. "While data is still being collected about these vaccines, we believe that in the vast majority of cases, the benefits outweigh the risks, and the vaccine is much safer than contracting COVID-19."
Dr. Emily Miller, a maternal fetal medicine physician at Northwestern Medicine, noted vaccine hesitancy is "pronounced for pregnant people."
Miller and her colleagues from the Chicago health system conducted a study that found COVID-19 does not damage the placenta during pregnancy.
"The placenta is like the black box in an airplane. If something goes wrong with a pregnancy, we usually see changes in the placenta that can help us figure out what happened,” Dr. Jeffery Goldstein, a Northwestern Medicine pathologist, said in a news release. “From what we can tell, the COVID vaccine does not damage the placenta.”
The study authors collected placentas from 84 vaccinated patients and 116 unvaccinated patients who delivered at Prentice Women’s Hospital in Chicago.