A Pharmacovigilance Study for AdimFlu-S (A/H1N1) Influenza Vaccine in Pregnant Women

This was a retrospective cohort study of pregnant women who had received the AdimFlu-S (A/H1N1) influenza vaccine during gestation period. Eligibility into the study was confirmed by chart review. If subject meets the eligibility criteria during the study period, data from the medical chart were extracted retrospectively from the date of vaccination and the infant (s) health status were followed until 8 weeks after the delivery.The unexposed cohort included pregnant women who did not receive any influenza vaccine during pregnancy. Within each participated study center, women who were gestation after April 2009 were randomly selected according to maternal age matching. The pregnancy outcome, including the status of delivery, abortion and gestational age, were extracted retrospectively by chart review.