Exposure to yellow fever vaccine in early pregnancy

We report on a data collection concerning exposure to yellow fever vaccine (YFV) during early pregnancy, ascertained through the European Network of Teratology Information Services (TISs) and the Pharmacovigilance Department of Pasteur Merieux Connaught (PMC). Six TISs had had no inquiry about YFV. Five submitted prospectively collected cases. Seventy-four cases were analyzed, 58 with a completed follow-up. Pregnancies ended in 46 births, five voluntary abortions and seven spontaneous abortions. Three newborns had minor anomalies and two had major defects (ureteral stenosis and triphalangeal hallux). Although the sample is too small to rule out a moderate increased risk of adverse reproductive effect of YFV, it gives no argument for such an effect and should lead to reassure pregnant women who might be inadvertently vaccinated.