Prenatal treatment of severe fetomaternal alloimmune thrombocytopenia

Prenatal treatment of fetomaternal alloimmune thrombocytopenia (FMAIT) in p reviously affected families is of great clinical importance. We report here our experience in the prenatal treatment of 15 severely thrombocytopenic f etuses. Thrombocytopenia was in 13 cases due to immunization to HPA-1a, in one case to HPA-5b, and in one case to HPA-6b. Thirteen fetuses received al together 34 intrauterine platelet transfusions, seven of them in combinatio n with maternal-administered intravenous gammaglobulin (IVIG) and two in co mbination with IVIG and prednisone. Six of the 13 fetuses had only one tran sfusion just prior to delivery. In our experience, IVIG seemed to be less effective than reported; only two fetuses of eight treated initially with weekly maternal-administered IVIG responded, and these were the mildest affected cases in the study. On the o ther hand, owing to the short survival time, weekly platelet transfusions c ould only partly maintain a safe platelet count in the four fetuses treated with serial intrauterine platelet transfusions. The number of transfusions needed to be limited because of the high cumulative risk associated with r epeated procedures. Three of 34 intrauterine platelet transfusions were ass ociated with near-loss of three different fetuses due to prolonged fetal br adycardia after the transfusion. In conclusion, overall neonatal outcome was good, with no mortality; among the study group there was no intracranial haemorrhage (evaluated by postnat al ultrasonography) compared with one case in their untreated siblings. How ever, the problem of the optimal treatment of FMAIT remains to be solved. F or the moment, the treatment of choice is a combination of maternal IVIG an d platelet transfusions in severely affected cases. Serial fetal blood samp lings (FBS) are needed in order to monitor the fetus with sufficient care.