Delayed intracranial hemorrhage in a newborn with alloininume thrombocytopenia after intensive prenatal treatment with serial platelet transfusions

Background. Fetal alloimmune thrombocytopenia (FAIT) is caused by maternal immunization against a fetal platelet antigen, most frequently HPA-1a (Zw(a ), Pl(A1)), and subsequent transplacental transfer of maternal IgG antibodi es into the fetal circulation. The fetus and the neonate are threatened by severe bleeding, particularly intracranial hemorrhage (ICH), which occurs i n 10-20% of all cases. We describe a case of FAIT due to immunization again st HPA-1a. Patients, Materials and Methods: At the beginning of pregnancy, the previously diagnosed HPA-1a antibody was confirmed by monoclonal antibo dy-specific immobilization of platelet antigen (MAIPA). Fetal blood specime ns were obtained by umbilical venipuncture. Fetal platelet counting and umb ilical blood sampling, first in the 22nd week of gestation, were combined w ith intrauterine platelet transfusion of HPA-la-negative platelet concentra tes of maternal or high-dose donor platelet concentrates. The thrombocytope nic fetus was treated by nearly weekly intrauterine platelet transfusions o f maternal or donor platelet concentrates and delivered by caesarean sectio n in the 35th week of gestation. Results: Our observations suggest that fre quent platelet transfusions in short intervals may be necessary to increase platelet counts in thrombocytopenic fetuses. The platelet count at birth w as 145,000/mul. The newborn did not show any signs of cutaneous bleeding. P ostpartal ultrasonic examination of the child's head revealed no signs of I CH. The platelet counts were examined daily during a 14-day period. Platele t counts reached a nadir of 70,000/mul at day 4. The child was discharged a t day 14 with 150,000 platelets/mul and without any hemorrhagic symptoms. N eurologic examination at the age of 6 months revealed subtle signs of a dev elopmental disturbance. Upon ultrasonic examination a parieto-occipital pos themorragic cyst was detected. Conclusion: Delayed ICH may occur in newborn s with FAIT. It remains to be elucidated whether this complication is a spe cific problem in children who had been treated with serial intrauterine pla telet transfusions for FAIT. However, for the early recognition of such del ayed ICH, short-term postpartal examinations during the first months of lif e are necessary.