A 37-year-old woman was admitted at 35 weeks’ gestation for mild toxemia of pregnancy which was not amenable to outpatient therapy. A previous and only pregnancy, 14 years prior to admission, was uncomplicated and resulted in the delivery of a 5 pound, 6 ounce infant who did well. The patient was Rh negative and Du negative, and the serum Rh-antibody titers were negative at 18, 27, and 30 weeks. Within 48 hours after admission, the patient’s blood pressure was normal, and previous proteinuria had disappeared with bed rest and phenobarbital. A serum Rh-antibody titer at this time was positive, and immediate amniocentesis was performed. The latter revealed dark meconiumand bile-stained amniotic fluid; therefore, labor was induced with amniotomy. After an uneventful labor during which fetal heart tones remained between 130 and 140 beats per minute, a 4 pound, 7 ounce infant was delivered. The delivery was controlled and spontaneous with minimal traction on the fetal head. At birth, the infant was markedly hydropic in appearance. Ascites and generalized edema were obvious. The umbilical cord was tightly wrapped around the neck, and only a few strands of what appeared to be spinal cord connected the head and fetal body. The infant, with an Apgar score of 2 for spontaneous respiration and heartbeat, died less than 2 minutes after birth. Histopathologic examination confirmed the clinical impression of severe hydrops fetalis. No other congenital abnormalities were found. The presence of partial focal expansion of the lungs was noted.