[Perinatally acquired thombocytopenias in the newborn infant].

The neonatal thrombocytopenias (TP) can be classified into congenital (i.e. inherited), connatal (i.e. acquired in utero), perinatal and postnatal forms. In the following survey, only the perinatal TP are considered in detail. These arise from transit of immune antibodies or coagulation-activating material across the placenta or from hypoxia due to placental insufficiency. The auto- and isoimmune TP are illustrated by relevant clinical observations. The existence of a platelet deficiency is not a rarity in newborns or in high-risk infants. If is often an important leading symptom for a side range of different conditions.