In utero intravascular transfusion for treating fetal hemolytic disease.

Technologic advances in ultrasound have led to the ability to access the fetal circulation in utero. Precise evaluation and accurate treatment of fetal hemolytic disease is now possible. This technique of in utero intravascular transfusion has several advantages. It uses a closed system that reduces the risk of infection and air embolus. The proximal extension tubing minimizes manipulation of the hub of the needle, which may lead to dislodgement of the needle, and permits a sampling port with minimal dead space between it and the fetal circulation. The HemoCue hemoglobinometer allows for rapid assessment of the concentration of fetal hemoglobin and, therefore, a shorter interval of time in which the needle is in the umbilical cord. This reduces the risks of trauma to the umbilical cord.