Posttransplant maternal anti-D: A case study and review

Plasma from a 35-year-old, D- woman was found to have anti-D, -C, and -G at 5 weeks' gestation and again at 8 weeks' gestation, when she presented with a nonviable intrauterine pregnancy. The anti-D titer increased with a pattern that suggested it was stimulated by the 8-week pregnancy. Six years before this admission, the patient's blood type changed from group O, D+ to group O, D- after a bone marrow transplant for aplastic anemia. Three years after transplant, the antibody screen was negative. After the patient was admitted for the nonviable pregnancy, the products of con-ception were found to be D+ by DNA testing for RHD. There were no documented transfusions or pregnancies during the interval in which anti-D appeared. The timing of the alloimmunization was unusual. In a subsequent pregnancy, fetal D typing was performed by molecular methods.