The fetal and neonatal consequences of maternal alloimmune thrombocytopenia

Alloimmune thrombocytopenia is a relatively common and under-recognized ent ity. Prospective screening studies have suggested that at least 1 in every 1000 babies will be affected. While the severity of prospectively identifie d neonates is not as great as those 'routinely' identified as newborns, the incidence of intracranial haemorrhage in the fetus and neonate is the high est for any immune thrombocytopenia. Diagnosis is complex for the laborator y in view of the large number of platelet antigens and the importance of ha ving sufficient numbers of typed controls. The importance of identifying th e affected newborn extends to the likely need for antenatal management of t he subsequent affected fetus. Studies to determine the optimal approach to this problem are ongoing. Ideally, prenatal screening of all pregnant women could be performed but this is not currently in practice.