COVID vaccines do not trigger pre-term birth, according to a large CDC study

• The COVID-19 vaccine isn't linked to an increased risk of preterm or small-for-gestational-age births.
• The reports adds to evidence that the vaccines are safe for pregnant women. Still, most remain unvaccinated.

COVID-19 vaccines in pregnancy aren't associated with any increase risk in preterm or small-for-gestational-age births, according to a large study out Tuesday from the Centers for Disease Control Prevention.

The report refutes common misconceptions and unfounded fears that experts say are holding many pregnant people back from getting the shot.

To conduct the study, researchers looked at the records of 46,079 women across eight healthcare organizations who were expected to give birth in the first half of 2021. Just over one-fifth of them had received at least one COVID-19 vaccine dose, typically during their second or third trimester.

When comparing birth outcomes, researchers found no significant differences in preterm birth and small-for-gestational age — meaning underweight for the length of pregnancy — rates between vaccinated and unvaccinated moms. That was the case regardless of when or how many doses the vaccinated women received.

While there were some gaps in data, like whether the women had experienced prior preterm births or COVID-19 infection, the CDC says the data adds to evidence that the COVID-19 vaccines are safe and important during pregnancy.

COVID-19 is especially risky in pregnancy, but vaccine hesitancy remains

One large August study found that, compared to healthy pregnant patients, those with the illness were more than five times as likely to be admitted to the ICU, more than 14 times as likely to need intubation or mechanical ventilation, and more than 15 times as likely to die.

Women with COVID-19 were also about 40% more likely to deliver prematurely.

And yet, as of December 2021, about 40% of pregnant people in the US were vaccinated, the CDC reports. Hesitation remains due to safety concerns and a lack of knowledge that the vaccines are recommended before or during pregnancy, surveys have found.

That, coupled with the rapid spread of the Omicron variant, is leading experts to double-down on their messaging to pregnant people. "Given those stakes and given those risks," Dr. Neel Shah, an OB-GYN at Harvard, recently told the Guardian, "again, the most important thing they can do to protect themselves is to get vaccinated.