The human papillomavirus (HPV) vaccine is recommended for all girls and women between 9 and 26 years of age. Currently, more than 72 million girls and women have been vaccinated worldwide. Although HPV vaccine is not recommended during pregnancy, it was inevitable that some young women will have received the vaccine when they are unknowingly pregnant. To determine whether HPV vaccination during pregnancy posed a risk to the fetus, researchers in Denmark examined the medical records of 650,000 women who were pregnant between 2006 and 2013 (Scheller NM, Pasternark B, Molgaard-Nielsen D, et. al. Quadrivalent HPV Vaccination and the Risk of Adverse Pregnancy Outcomes. N Engl J Med 2017;376:1223-33).
The researchers found that receipt of HPV vaccine during pregnancy did not increase the risk of adverse outcomes including spontaneous abortion, stillbirth, major birth defects, small size for gestational age, low birth weight, or preterm birth. Although no reasonably biological mechanism has been proposed for why HPV vaccination during pregnancy would negatively affect the fetus, it is reassuring to have data that support the safety of HPV in that situation.
The authors of the study concluded, “Quadrivalent HPV vaccination during pregnancy was not associated with a significantly higher risk of adverse pregnancy outcomes than no such exposure.”