TOPLINE

A long follow-up study showed that, among women, human papillomavirus (HPV) vaccination during early adolescence or as cross-vaccination during late adolescence was not associated with an increased risk for miscarriages or other adverse early pregnancy outcomes.

METHODOLOGY

• Using data from nationwide Finnish registries, researchers conducted a longitudinal cohort study to compare the incidence of miscarriages or other abnormal early pregnancy outcomes between women with HPV vaccination and those without vaccination.
• The study included 20,426 women born between 1992 and 1995 who participated in a community-randomised HPV vaccination trial across 33 municipalities in 2007; 19,473 age- and community-aligned unvaccinated women born in 1990-1991 were also included as control participants.
• During the vaccination trial, participants received either the HPV vaccine or hepatitis B virus (HBV) vaccine at ages of 12-15 years, and some participants who initially received the HBV vaccine later underwent HPV cross-vaccination at the age of 18.5 years and were considered "cross-vaccinated."
• Participants were followed up for 11 years.

TAKEAWAY

• A miscarriage occurred in 1.6% of HPV-vaccinated women and 1.3% of cross-vaccinated women, compared with 5.3% of unvaccinated women, with a significant difference observed between cross-vaccinated and unvaccinated women (P < .0001). Miscarriage rates were highest among women aged 25-27 years, ranging from seven to eight per 10,000 person-years in the vaccinated group vs 14 per 10,000 person-years in the unvaccinated group.
• No miscarriages were reported within the first 6 years after HPV or HBV vaccination at ages of 12-15 years. Among those who underwent cross-vaccination at the age of 18.5 years, four miscarriages were reported within 24 months, none of which occurred during the first 6 months.
• Ectopic pregnancy rates remained low and comparable across all cohorts, ranging from 0.6% to 1.0%.
• Among women with a history of abnormal pregnancy outcomes, live birth rates were 55.6% for HPV-vaccinated women and 70.3% for unvaccinated women.

IN PRACTICE

"[The study] findings provide further reassurance on the reproductive safety of HPV vaccination, both when administered in early adolescence and as cross-vaccination in late adolescence," the authors wrote.

"Continued surveillance and future studies incorporating detailed lifestyle and clinical data will help further refine our understanding of HPV vaccination and reproductive health outcomes," they added.

SOURCE

This study was led by Tiina Koivisto, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland. It was published online on August 12, 2026, in the European Journal of Public Health.

LIMITATIONS

Women who participated in the HPV vaccination trial may have differed from the unvaccinated cohort in health awareness, lifestyle habits, or other characteristics, introducing potential selection bias. The registry lacked data on lifestyle factors such as smoking, alcohol use, BMI, and contraceptive use.

DISCLOSURES

The study received partial support from state funding for university-level health research and Tampere University Hospital, Wellbeing Services County of Pirkanmaa, and others. One author declared receiving grants for his vaccination studies from Merck & Co., Inc. and GSK Biologicals.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.