Safety of the 9-valent human papillomavirus vaccine in pregnancy based on the vaccine adverse event reporting system

Abstract

Current guidelines recommend against administering the 9-valent human papillomavirus (HPV) vaccine during pregnancy due to limited safety data. We examined adverse events reported in patients receiving the 9-valent HPV vaccine during pregnancy. The Vaccine Adverse Events Reporting System (VAERS) database was queried for “exposure during pregnancy” to the 9-valent HPV vaccine. Cases were excluded if there was no information on pregnancy in the report or the patient was not pregnant at the time of vaccination. Individual reports were reviewed and data were extracted on gestational age and adverse pregnancy events. From the 285 reports identified, 273 were included. 40.3% (110/273) of the reports stated that there were no adverse events following vaccination. There were eight reports of mild maternal reactions (most commonly injection site pain) and one report of a serious reaction (angioedema). The majority of reports (257/273, 94.1%) did not include the pregnancy outcome. There was one case of vaginal bleeding, four miscarriages, one elective abortion, no stillbirths, and two congenital anomalies. There were seven reports of live births. 61.5% (168/273) of the reports included gestational age at the time of vaccination. Few cases of pregnancy-related adverse events were identified following 9-valent HPV vaccine administration. The VAERS database is an electively reported database; thus, the incidence of events could not be determined, and many reports were incomplete. Despite these limitations, the low numbers of adverse events are reassuring. Clinical trials are warranted to conclusively examine the safety and efficacy of HPV vaccination during pregnancy.

Keywords

Human papillomavirus / Vaccination / Vaccine Adverse Events Reporting System / Pregnancy / Gestational age / Congenital vaccine exposure

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