Studies Suggest COVID Vaccines Have No Impact On Pregnancy Or Fertility

by Kristine Cannon

Two new studies help emphasize that COVID vaccines are not dangerous during pregnancy

As scientists continue testing the COVID-19 vaccines on groups of people initially excluded from clinical trials, like children and pregnant people, we continue to learn more about how the various vaccines impact said groups. In February, for instance, we learned that COVID-19 antibodies can be passed to babies in utero; and earlier this week, the FDA permitted use of the Pfizer vaccine in kids ages 12 to 15, after testing the vaccine in children back in March. Now, a recent study published in JAMA today states that the COVID-19 vaccines protect pregnant women — and they may also have benefits for infants.

Published on May 13, the “Immunogenicity of COVID-19 mRNA Vaccines in Pregnant and Lactating Women” study suggests that vaccinated women can pass protective antibodies to their fetuses through the bloodstream, as well as to their infants through breast milk. Further, the study suggests that both the Pfizer-BioNTech and Moderna vaccines produce immune responses in pregnant and lactating women. They’re also likely to provide at least some protection against two coronavirus variants.

“Vaccination of pregnant people and lactating people actually leads to transfer of some immunity to their newborns and lactating infants,” says Dr. Ai-ris Y. Collier, a physician-scientist at Beth Israel and one of the authors of the study.

Another study — published in the journal Obstetrics & Gynecology on Tuesday — found zero evidence of the Pfizer vaccine nor Moderna vaccine damaging the placenta during pregnancy. The shot also has no impact on fertility, menstruation or puberty, according to the study.

“We can shift our framework from, ‘Let’s protect pregnant people from the vaccine,’ to ‘Let’s protect pregnant people and their infants through the vaccine,’” Dr. Emily S. Miller, co-author of the placenta study, tells The New York Times. “I think that’s really powerful.”

The JAMA study involved 103 women who received either the Pfizer or Moderna vaccine between December 2020 and March 2021. Thirty of them were pregnant, and 16 of them were lactating, while 57 were neither. As for the placenta study, the research team examined placentas from 200 women who gave birth between April 2020 and April 2021. Of the women, 84 received either the Pfizer or Moderna vaccine during pregnancy.

“We don’t see any signals that suggest the placenta is getting injured from the vaccine,” Miller tells the Chicago Tribune. “This builds upon rapidly emerging data that emphasizes that the vaccine is not dangerous during pregnancy.”

“Overall, it’s good news,” Dr. Dan Barouch, a study author and virologist at Beth Israel, tells The New York Times. “And it increases the data that suggests that there is a substantial benefit for pregnant women to be vaccinated.”