HPV vaccination before age 17 may confer a modest yet still significant reduction in the likelihood of spontaneous preterm birth, international researchers have found.

Results from their registry-based study involving more than 240,000 women showed a 13% lower risk with early age vaccination compared to those who were unvaccinated.

This protective effect did not extend to those vaccinated at or after 17 years, whose risk was comparable to that of unvaccinated women, the authors say.

Previous studies from Australia and Finland point to a similar association between HPV vaccination and preterm birth, whereas data from Scotland has shown no beneficial effect.