Neonatal alloimmune thrombocytopenic purpura.

We reviewed 58 literature reports of neonatal alloimmune thrombocytopenic purpura (NAITP). The mortality rate was 9%. The total incidence of suspected intracranial hemorrhage was 28%. We reviewed 17 sibship cases for the relation of birth order to treatment and outcome. Among firstborn affected infants (n = 17) the mortality rate and incidence of central nervous system sequelae were 24 and 47%, respectively, compared to rates of 5 and 15%, respectively, in their younger affected siblings (n = 20). The improved outcome in the latter group appeared to be related to more frequent cesarean section delivery and more frequent and earlier use of corticosteroids and maternal platelet transfusions in the neonate. Sensitive assays of maternal platelet alloantibody are now available, but they lack specificity for NAITP affecting the current gestation. There are two reports in which sensitive assays revealed rising titers of maternal platelet alloantibody during advancing gestation. We propose further study to determine if this is specific for the antepartum diagnosis of NAITP.