[Immunothrombocytopenia of the newborn caused by platelet-specific antibodies (anti-P1A1) (author's transl)].

For the first time in the German speaking area 8 cases of neonatal immunothrombocytopenia caused by platelet-specific P1A1 antibodies could be ascertained. The disease is caused by fetomaternal incompatibility against platelet antigens. All mothers were healthy. The children showed a postnatal tendency for petechial haemorrhages. Cerebral haemorrhages occurred in two cases. Optimal treatment consists of administration of P1A1-negative platelets (perhaps of the mother). Demonstration of platelet antibodies is possible nowadays by adequate serological methods.