CDC study finds no link between COVID-19 vaccines and premature birth

NEW HAVEN, Conn. — Although pregnant women have a higher risk of developing severe COVID-19 illness, many are still hesitant to get the coronavirus vaccine. A new study may put some fears to rest, finding that the vaccinations don’t lead to a higher risk of premature birth.

As of September 2021, just one in three pregnant women (31%) in the United States have received at least one vaccine dose. Common concerns regarding vaccination focus on the safety of the vaccine and any long-term consequences for the baby.

The Centers for Disease Control and Prevention (CDC) explored this concern, looking at any potential risks coming from getting the COVID-19 vaccine on a woman’s pregnancy. Premature birth — or deliveries taking place earlier than 37 weeks — and a condition called small-for-gestational-age both increase the risk of death and long-term disability for infants. However, the new findings confirm that COVID vaccines do not raise the risk of either problem occurring.

Researchers collected data from eight organizations in the Vaccine Safety Datalink project, examining the link between premature birth among vaccinated and unvaccinated pregnant women between the ages of 16 to 49.

The study also tracked the pregnancies of 10,064 individuals who had at least one COVID-19 vaccine dose during pregnancy. Nearly the entire group (98.3%) received their vaccination during their second or third trimesters. About 1.7 percent received a COVID shot during their first trimester.

Approximately 96 percent of pregnant women received an mRNA COVID-19 vaccine, which include the Pfizer and Moderna injections.

Vaccinations at any point of a pregnancy don’t increase preterm births

Results show that regardless of which trimester pregnant women receive their COVID-19 vaccines or how many doses they have, there was no difference in the rate of premature births between vaccinated and unvaccinated women.

For every 100 births, there were about 6.6 premature births in vaccinated women. In contrast, there were 8.2 premature births in unvaccinated women.

“Getting vaccinated against COVID-19 is important for preventing severe illness in pregnant people,” says Heather Lipkind, associate professor of obstetrics, gynecology, and reproductive sciences at the Yale School of Medicine, in a university release. “With the increasing rates of COVID-19 in our community we are encouraging pregnant people to get vaccinated.”

Researchers published their findings in the CDC’s journal Morbidity and Mortality Weekly Report.

About the Author

Jocelyn Solis-Moreira

Jocelyn is a New York-based science journalist whose work has appeared in Discover Magazine, Health, and Live Science, among other publications. She holds a Master’s of Science in Psychology with a concentration in behavioral neuroscience and a Bachelor’s of Science in integrative neuroscience from Binghamton University. Jocelyn has reported on several medical and science topics ranging from coronavirus news to the latest findings in women’s health.

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