Intra-uterine exchange transfusion under ultrasound guidance.

Thirty intra-uterine exchange transfusions (I.U.E.T.) under ultrasound guidance were performed on 15 pregnancies in 14 severely Rh-sensitized women. Our technique and a new method of catheterization of the umbilical cord are described. I.U.E.T. were commenced at 19-34 gestational weeks and repeated up to 5 times at 15 to 60 days intervals. The lowest pretransfusion fetal hemoglobin was 3 milligrams at 25 weeks. All the hydrops (4 cases) reversed a few days after the first procedure. The survival rate is 50% for hydropic fetuses and 66.6% for all cases. This technique avoids fetal hypervolemia and also too repetitive procedures by quick renewal of red cells. Catheterization offers a simple and safe access to the umbilical vein even with important fetal movements.