Manufacturers' postmarketing safety surveillance of influenza vaccine exposure in pregnancy

Pregnant women are at increased risk for hospitalization and death with influenza infection. The limited data on safety and effectiveness of influenza immunization in pregnancy emphasizes the importance of developing new and well-designed studies and of enhancing safety surveillance in pregnant women who are vaccinated with licensed influenza vaccines. Pregnancy exposure registries aim to collect and maintain data on the effects of marketed drugs and vaccines, when prescribed in pregnancy or during breastfeeding, on the women themselves and their children. Women who are prescribed a medication or vaccine as part of their routine clinical care can be enrolled directly or through reporting health care providers on a voluntary basis. Such registries generally are established for products that are intended for use by adolescents and adults and are a key component of the safety monitoring of licensed products. This article reviews some of the pregnancy registries that have been established for US-licensed vaccines, which includes influenza vaccines, and other postlicensure safety surveillance efforts for monitoring safety in vaccinated pregnant women.