[Alloimmune thrombocytopenia in the newborn infant caused by maternal PlA1 antibodies].

The case of pregnant woman, whose first child was born with neonatal alloimmune thrombocytopenia (NATP) and PlA2/PlA1 constellation, is used as an example to draw up a programme for the care of pregnant women whose children are expected to be born with NATP. In one of 2,000 to one of 3,000 cases, the PlA1-positive foetal platelets cause a sensitization of the PlA1-negative mother. Transplacental passage of maternal IgG alloantibodies leads to accelerated destruction of foetal platelets. The pathophysiologic process is similar to Rh-erythroblastosis foetalis. The infants show symptoms ranging from cutaneous manifestations to intracranial haemorrhages.