INTRODUCTION: Human papillomavirus (HPV) 6/11/16/18 vaccine (qHPV vaccine) is a quadrivalent vaccine for the prevention of cervical, vulvar, and vaginal cancers; their respective precancers; and genital warts caused by these vaccine types. As of December 2012, more than 50 million doses of qHPV vaccine have been distributed in the United States where the majority of exposures occurred. Because the vaccine is recommended for women of childbearing age, Merck and Co, Inc established the Pregnancy Registry for qHPV vaccine in 2006. A 6-year summary of the safety profile of pregnancy exposures and outcomes to the qHPV vaccine is presented.
METHODS: Enrollment criteria to the registry included an identifiable patient and health care provider from the United States, France, or Canada exposed within 1 month before the date of onset of the last menstrual period or at any time during pregnancy. Outcomes of interest were pregnancy outcomes and birth defects. Prospectively reported cases (reported before the outcome of the pregnancy was known) were used for rate calculations because retrospectively reported cases (reported after the outcome is known) are considered to be inherently biased toward abnormal outcomes. The Metro Atlanta Congenital Defects Program methodology is used to compare and define birth defects and estimate rates.
RESULTS: For the 1,573 prospective reports with known natural pregnancy outcomes, 1,452 (92%) were live births. Of 1,460 neonates, 1,381 (95%) were born without birth defects. The prevalence of major birth defects was 2.5 per 100 live-born neonates (95% confidence interval [CI] 1.7–3.4) and compares favorably with the observed Metro Atlanta Congenital Defects Program rate of 2.67 per 100. The overall rate of spontaneous abortion was 6.7 per 100 outcomes (95% CI 5.5–8.2). There were 12 fetal deaths (0.8/100 outcomes, 95% CI 0.4–1.4) not clustered around a specific abnormality.
CONCLUSION: This is likely the largest HPV vaccine pregnancy registry to date. Rates of spontaneous abortions and major birth defects were not greater than the Metro Atlanta Congenital Defects Program unexposed population rates. Analysis of 6 years of pregnancy registry data shows no adverse signals. The qHPV vaccine is not recommended for use in pregnant women.
Financial Disclosure: Mary Ann Goss, Fabio Lievano, Margaret M. Seminack, and Adrian Dana—These authors have a relevant financial relationship with the following commercial interest: Employee: Merck.
© 2014 by The American College of Obstetricians and Gynecologists.