A 15-year-old primigravida registered late for antenatal care (23 weeks). Ultrasound examination revealed massive idiopathic fetal ascites necessitating in utero paracentesis at 27 weeks. The family was socially dislocated, and the patient's alcoholic father doted on her. A live female fetus with ascites and multiple congenital abnormalities was delivered at 34 weeks. Following repeated hospitalization, the infant died of pneumonitis, at 5 months of age; autopsy could not determine the cause of the ascites. Young pregnant teenagers from broken homes with doting behavior from an alcoholic father should be suspected of being incest victims.