Cervarix™ is a prophylactic human papillomavirus (HPV)-16/18 vaccine for the prevention of cervical cancer. It contains GSK Biologicals' proprietary Adjuvant System AS04. The objective of this study was to investigate the effects of Cervarix™ and of AS04 on female fertility and pre- and post-natal development in Sprague Dawley rats. Female rats were injected with vaccine, AS04, or saline 30 days before mating and on Gestation Days 6, 8, 11 and 15. Each dose of vaccine was one-fifth the human dose volume. Treatment of rats with vaccine or AS04 was not associated with any systemic toxicity and had no impact on female fertility. There were no adverse effects on pre- or post-natal development of litters from treated rats, as judged by fetal evaluation at Gestation Day 20, and growth and survival of pups to postnatal Day 25. These results support the use of the vaccine in the targeted human population.