The management of severe rhesus isoimmunization by fetoscopic intravascular transfusions.

Twenty-five severely rhesus-isoimmunized fetuses, including 15 with hydrops fetalis, underwent a total of 77 intrauterine transfusions between 19 and 32 weeks' gestation. Fifty-eight of the procedures were fetoscopically directed intravascular transfusions, nine were ultrasound-guided intraperitoneal transfusions, and 10 were a combination of intravascular transfusion, fetal paracentesis, and intraperitoneal transfusion. The average number of antenatal procedures per patient was three (range, one to five). The survival rate for the 19 fetuses that received their initial intrauterine transfusion at or before 25 weeks' gestation was 84%; 11 of the 13 hydropic fetuses and five of the six fetuses without antenatal evidence of hydrops survived. In six cases hydrops fetalis was reversed in utero. The outcome in patients referred after 25 weeks' gestation was poor; neither of the two hydropic fetuses and only two of the four nonhydropic ones survived, which suggests the importance of early referral to a team experienced in the management of this problem. However, most of these fetal losses occurred early in the series. Seven of the 20 neonates were hydropic, and nine had severe thrombocytopenia (platelet count, less than 50,000 X 10(6)/L). The mean cord blood hematocrit and bilirubin of the neonates were 25.1% and 82 mumol/L, respectively. The babies required a total of 69 exchange transfusions (range, 0 to 9) and 68 simple transfusions (range, 0 to 25). One newborn infant who had had ultrasound evidence of hydrops fetalis at 22 weeks' gestation did not require any exchange transfusions. Nine patients required intermittent positive pressure ventilation (eight had respiratory distress syndrome and one had apnea) for a range of 1 to 86 days. The neonatal survival rate was 90% (18/20).