Results of a recent population-based study found that unintended human papillomavirus (HPV) vaccination during pregnancy does not increase the risk of spontaneous abortion, stillbirth, or infant mortality.
The study analyzed all pregnancies in Denmark between October 2006 and December 2014 in women born between 1975 and 1992. HPV vaccination, pregnancy outcomes, and infant mortality information was obtained using personal identification numbers from nationwide health registries.
The exposure window for the outcome of spontaneous abortion began 4 weeks before the conception date and continued until 22 weeks of gestation. For the stillbirth and infant mortality outcomes, the exposure window began 4 weeks before the conception date and continued until birth.
The study authors stated, “We included 522,705 pregnancies for the outcome spontaneous abortion (7,487 exposed to at least 1 dose during pregnancy); 351,878 births (5,262 exposed to at least 1 dose during pregnancy) for the stillbirth; and 350,739 live births (5,245 exposed to at least 1 dose during pregnancy) for infant mortality.”
Results of the study found that there was no significant increase in the rate of spontaneous abortion in vaccinated pregnant women compared to those who were not vaccinated. Additionally, the study authors reported finding no association between HPV vaccination in pregnancy with stillbirth (adjusted odds ratio [OR] 0.96; 95% CI: 0.57, 1.61) or infant mortality (adjusted hazard ratio [HR] 0.94; 95% CI: 0.53, 1.67). “A secondary analysis showed no association between number of doses and timing of administration (i.e. vaccination before or during pregnancy) and an increased risk of spontaneous abortion,” the study authors added.
According to the results of this population-based study, HPV vaccination during pregnancy is not associated with an increased risk of spontaneous abortion, stillbirth, or infant mortality.
Faber, MT et al. Adverse pregnancy outcomes and infant mortality after quadrivalent HPV vaccination during pregnancy. Vaccine. DOI: doi.org/10.1016/j.vaccine.2018.11.030.