[Three special cases of pregnancy outcome to reflect about].

Background: Neonatal alloimmune thrombocytopenia (NAITP) may be a serious condition with prenatal intracranial haemorrhages. Our three cases of serious NAITP raise the question of whether pregnant women should be screened for thrombocyte type and then for HPA-1a antibodies if they are HPA-1bb positive.

Case Reports: We present three cases of severe NAITP in which screening and follow up of HPA-1a antibodies prevented serious sequelae in two of the siblings. The first child was a stillbirth with congenital hydrocephalus caused by an intraventricular haemorrhage. In the second pregnancy, the mother was found to be platelet type HPA-1bb with platelet antibodies against HPA-1a. The antibody level was extremely high and an elective caesarean section was performed four weeks before term. The platelet count at birth was 3 and 5 x 10(9)/L and a transfusion of matched platelets was immediately performed followed by infusion of intravenous immunoglobulin. In the third pregnancy, an intracerebral haemorrhage was detected by ultrasound at 27 weeks of gestation. The mother was given steroids to induce foetal lung maturation followed by a caesarean section in week 28. The platelet count was 6 x 10(9)/L. The child was transfused with compatible platelets and given an infusion of intravenous immunoglobulin.

Outcome: None of the two children have developed any psychomotor sequelae by the age of five and three years, respectively. The importance of screening for platelet type and anti-platelet antibodies and mode of delivery is discussed.