Questioning Universal Use of O- Red Blood Cells in Intrauterine Transfusions

In the setting of maternal alloimmunization to antigen(s) on fetal red blood cells, significant fetal anemia may develop, and an intrauterine transfusion may be required. When selecting a blood product for intrauterine transfusion, the priority should be crossmatch compatibility with the mother. Preventing fetal alloimmunization is not practical or necessary. Universal use of O- red blood cells is not appropriate for pregnant women who are alloimmunized to c or e antigens and require an intrauterine transfusion. Essentially, 100% of people who are D- are homozygous for both c and e antigens. Thus, it is logistically impossible to find red blood cells that is D-c- or D-e-, and O+ red blood cells is necessary in the context of maternal alloimmunization to c or e antigens.