Neonatal thrombocytopenia has benefited from the advances achieved during the last few years in platelet immunology and foetal therapy. The major risk of the disease is cerebral haemorrhage resulting in death or neurological sequelae. Establishing the aetiological diagnosis of immune thrombocytopenia makes it possible nowadays to apply the appropriate treatment and eventually to take care of future pregnancies. Treatments in utero of foeto-maternal alloimmunization have radically altered the natural course of foetal thrombocytopenia, thereby permitting the management of pregnancies at risk. On the other hand, so far no prenatal treatment has proved to be effective against thrombocytopenia due to maternal autoimmunity.