Lymphocytic choriomeningitis virus (LCMV), a rodent-borne arenavirus, is an often undiagnosed human fetal teratogen. We describe a neonate born with hydrocephalus and chorioretinitis after maternal second-trimester symptomatic LCMV infection. Previously reported affected infants are reviewed. We strongly suggest that obstetricians counsel their pregnant patients regarding the potential hazard that contact with infected pet, laboratory, and household mice and hamsters poses to pregnant women and their unborn children.