Does the HPV Vaccine Protect Against Premature Birth? A New Study Suggests It Might

A new study published in The BMJ found that people who had received the HPV vaccine before pregnancy were less likely to give birth early than those who were unvaccinated.

What did the study find?

Researchers looked at 624,713 births in Sweden between 2006 and 2023 and compared pregnancy outcomes in patients who had received the HPV vaccine with those in patients who had not. The clearest finding involved babies born too early.

A full-term pregnancy lasts about 40 weeks. Babies born before 37 weeks are considered premature, and those born even earlier than that can face more serious health problems.

The results show that people who had gotten the HPV vaccine had:

• 5% lower odds of giving birth prematurely (before 37 weeks) than unvaccinated people
• 15% lower odds of giving birth very prematurely (between 28 and 31 weeks) than unvaccinated people
• 5% lower odds of experiencing spontaneous preterm birth (meaning labor started on its own rather than being started by a medical procedure) than unvaccinated people

The researchers also found that the age at which someone received the vaccine seemed to matter. People vaccinated before age 17 were 10% less likely to have a preterm birth and 11% less likely to have a spontaneous preterm birth compared with those who weren’t vaccinated.

Today’s HPV vaccine protects against nine types of HPV, including those responsible for most HPV-related cancers and genital warts. The people in this study received an older vaccine that protected against four types.

Most HPV infections go away on their own. But some last longer and can cause health problems. HPV causes nearly all cases of cervical cancer. It can also cause cancers of the vulva, vagina, penis, anus, and back of the throat.

How does HPV affect pregnancy?

Researchers are still learning how HPV may affect pregnancy. Studies have found a few possible connections.

First, some studies suggest that HPV may affect the development of the placenta, the organ that provides oxygen and nutrients to a developing fetus.
Second, certain types of HPV can cause abnormal cells to develop on the cervix. Sometimes these cells need to be removed to be tested or to prevent cervical cancer. Other studies have linked a history of these procedures to complications in future pregnancies.

Still, researchers don’t yet know exactly why vaccinated people in this study had fewer pregnancy complications, and the study doesn’t prove that the HPV vaccine prevents premature birth. There may have been other reasons why the vaccinated group had fewer complications.

Should you get vaccinated?

The HPV vaccine is routinely recommended for people ages 11 to 26, but it can be given as young as 9 or as old as 45. The vaccine works best before someone is exposed to HPV, but people who are already sexually active can still benefit. If you weren’t vaccinated as a tween or teen, ask your health care provider about catch-up vaccines.

The HPV vaccine isn’t recommended during pregnancy.

We already have excellent reasons to get the HPV vaccine: It prevents cancer. This new research suggests it might also help contribute to healthy pregnancies. More research is needed, but the findings give us another reason to be enthusiastic about HPV prevention.