Immune thrombocytopenia in the foetus and the newborn: diagnosis and therapy.

Thrombocytopenia is a common condition in intensive care units. However the frequency of neonatal thrombocytopenia in all newborns (< 150 x 10(9)/L) has been estimated at 1-4%. Foetal/neonatal immune thrombocytopenia due to the transplacental passage of maternal antiplatelet IgG is a transient passive disease in an otherwise healthy newborn. The major risk of severe thrombocytopenia is intracranial haemorrhage (ICH) leading to death or neurological impairment. The principal aim in the management of the affected infants is to prevent the deleterious consequences of severe thrombocytopenia. Autoimmune thrombocytopenic purpura (AITP) in pregnant women can induce moderate or severe thrombocytopenia in the foetus or the newborn whatever the mother's disease status. Foetal thrombocytopenia can occur as early as 20 weeks of gestation. The frequency of ICH has been estimated to be 1-3% of cases. Foetal thrombocytopenia cannot be prevented. After birth, thrombocytopenia usually worsens during the first days of life. Postnatal management is usually ly of intravenous immunoglobulins. Neonatal alloimmune thrombocytopenia is considered to be the platelet counterpart of haemolytic disease of the newborn. Severe bleeding in the central nervous system and death (10% of cases) or neurological sequelae (20% of cases) may occur. The incidence of neonatal alloimmune thrombocytopenia has been estimated at 1 per 800-1000 live births. After birth, maternal platelet transfusion is the treatment of choice. Due to the high risk of recurrence of foetal thrombocytopenia in subsequent pregnancies, protocols for antenatal management including maternal therapy with intravenous immunoglobulins and/or corticosteroids, or in utero transfusion have been proposed.