Continuing controversy in alloimmune thrombocytopenia: fetal hyperimmunoglobulinemia fails to prevent thrombocytopenia.

Two patients with severe alloimmune thrombocytopenia were managed by weekly intrauterine platelet transfusions at 25 to 36 weeks. In one patient high-dose immunoglobulin was also administered weekly to the mother, and high maternal and fetal immunoglobulin levels were achieved. Fetal platelet counts were similar in both patients. The only variable that affected fetal platelet concentration was the posttransfusion platelet count from the previous transfusion.