Extended matched intrauterine transfusions reduce maternal Duffy, Kidd, and S antibody formation.

Background: Severe alloimmune hemolytic disease of the fetus is treated with intrauterine transfusions (IUTs). Despite C, c, E, e, and K matching between mother and donor, IUT results in new antibodies in approximately 25% of women. Newly formed Fy(a), Fy(b), Jk(a), Jk(b), and S antibodies are in 83% presumably induced by the IUT donor.