Successful treatment of extremely severe fetal anemia due to Kell alloimmunization.

Background: Repeated plasmapheresis was used to prevent fetal death from severe anti-Kell alloimmunization until intrauterine transfusions were feasible.

Case: Repeated maternal plasma exchanges (N = 40) beginning at 7 weeks' gestation were used to treat severe anti-Kell alloimmunization. Ultrasound examination at 19 weeks' gestation revealed diffuse hydrops in this fetus (umbilical venous hemoglobin, 1.2 g/dL), which then required nine intrauterine transfusions through 34 weeks. A healthy 3840-g girl was delivered by cesarean delivery at 36 weeks. Despite aplastic anemia during the first 3 months of life, she is healthy and has no observable abnormalities at age 8.

Conclusion: A highly aggressive course of plasmapheresis and intrauterine transfusions can successfully treat fetal anemia caused by anti-Kell alloimmunization even when fetal hemoglobin is extremely low.