Between January 1987 and March 1989, 22 fetuses with severe hemolytic disease were treated with 64 ultrasound-guided intrauterine intravascular transfusions. Eighteen infants survived and are doing well. In 12 fetuses, hydropic changes were present at the first transfusion; 9 of these survived. In 8 of the 10 fetuses with a gestational age less than 26 weeks, intrauterine treatment was successful.