HPV vaccination linked to lower risk of preterm birth
Women vaccinated against HPV before their first pregnancy were less likely to give birth prematurely, according to a Swedish register study from Karolinska Institutet published in The BMJ.
October 14, 2026
The study covered 624,713 pregnancies among first-time mothers aged 16 to 35 in Sweden between 2006 and 2023, of whom 92,620 had received the quadrivalent HPV vaccine before becoming pregnant. Compared with unvaccinated women, vaccinated women were around 5% less likely to give birth prematurely and around 15% less likely to give birth very prematurely. The associations were stronger among women vaccinated before the age of 17.
As an observational study, it cannot show that vaccination caused the lower risk, the researchers note. The work was carried out with the University of Gothenburg, Sahlgrenska University Hospital and the Norwegian Institute of Public Health.
“Even a relatively small reduction in the risk of preterm birth can be significant at a population level, given that HPV vaccination is administered to millions of young people worldwide,” says Jiayao Lei, assistant professor at the Department of Medical Epidemiology and Biostatistics at Karolinska Institutet.
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Source: Karolinska Institutet
Published: October 14, 2026
