Clinical History.—A 2,500-gm (5.6-lb) boy was born by elective cesarean section after 38 weeks' gestation. The mother was gravida 4 Para 3, and O Rh negative. Rh sensitization had been documented in the mother during her second and subsequent pregnancies. The last previous pregnancy had terminated in the spontaneous birth of an 820-gm (1.8-lb) stillborn. The present pregnancy was carried to 38 weeks; during that time, six separate intrauterine transfusions were performed.
Physical Examination.—At birth, the patient gave a brief initial cry, then spontaneous respirations ceased. The heart rate decreased to 80 beats per minute and he rapidly became cyanotic. The Apgar score at one minute was 4. He was intubated and successfully ventilated with use of a bag for approximately 2 minutes before the onset of spontaneous respirations and a return of the heart rate to 160 beats per minute. The Apgar score at 5 minutes was