The HPV vaccine is best known for protecting against cervical cancer. But, it may have another major benefit: reducing the risk of serious pregnancy complications.A large Swedish study looked at more than 624,000 first-time births.About 93,000 of the women were vaccinated against HPV, or the human papillomavirus, a common, sexually transmitted infection that can cause precancerous and cancerous changes.Those who were vaccinated had lower odds of several complications, including preterm and very preterm birth, the amniotic sac rupturing too early, and having a severely small baby.The association was generally stronger among women vaccinated before age 17. They had about 10% lower odds of preterm birth and 11% lower odds of spontaneous preterm birth.The researchers say vaccination may help by preventing HPV infection and reducing the need for procedures to remove abnormal cervical tissue. These procedures have been linked to a higher risk of preterm birth.Because this was an observational study, it can’t prove cause and effect, but researchers say the study’s large size, high-quality data and long follow-up strengthen the findings.The authors say, “Our results suggest that human papillomavirus vaccination is not only safe with respect to pregnancy outcomes but may also confer additional benefits by reducing the risk of adverse events.”Source: BMJ Open AccessAuthor Affiliations: Karolinska Institutet, University of Gothenburg, Sahlgrenska University Hospital, Norwegian Institute of Public Health .Sign up for our weekly HealthDay newsletter