Appearance of maternal anti-JK a antibody following intrauterine transfusions and amniocentesis.

A case is presented that suggests that intrauterine transfusion carries the risk of sensitization to red cell antigens other than Rho. In this case intrauterine transfusions of JK a-positive red cells were followed by the appearance in the mother's serum of anti-JK a, an antibody known to cause hemolytic disease of the newborn. The use of the mother as a donor of red cells for her fetus will circumvent the problem of further maternal sensitization.