[Neonatal alloimmune thrombocytopenia. Diagnosis and follow-up in pregnancy].

Neonatal alloimmune thrombocytopenia is present in every 2,000-3,000 pregnancy, that is in 20-30 pregnancies in Norway each year. Anti-HPA la antibodies are usually present in severe alloimmune thrombocytopenia in foetus and neonates. Pregnant women are not screened for the presence of anti-HPA la antibodies. Neonatal alloimmune thrombocytopenia can be suspected in newborn children who show signs or symptoms of thrombocytopenia. Laboratory investigation for neonatal alloimmune thrombocytopenia should be performed if the newborn child shows signs of bleeding, in women who have had multiple abortions and after stillbirth. Examples are presented from laboratory investigations in seven families with children who have thrombocytopenia.