How do we treat fetal and neonatal alloimmune thrombocytopenia?

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a potentially devastating disease, seen in one in 800 to 1000 neonates. FNAIT is the most common cause of early-onset isolated severe neonatal thrombocytopenia in maternity wards. The complication of this disorder most to be feared is intracranial hemorrhage, leading to death or to neurologic sequels. As there is no systematic screening of at-risk pregnancies, FNAIT is often discovered when signs of bleeding are observed during pregnancy or at delivery. Platelet transfusion is required in case of bleeding or severe thrombocytopenia (<30 × 10(9) /L) during the 48-hour-postdelivery period. Diagnosis of alloimmunization is important for management of the index case and for subsequent pregnancies, due to the increasing severity of this syndrome as it recurs. Noninvasive antenatal therapy is based on maternal perfusion of intravenous immunoglobulins and risk stratification. In our experience, the addition of corticoids during the last trimester significantly improves the efficiency of treatment. Follow-up of antibody concentration during pregnancy may constitute a useful variable for therapy effectiveness.

Is it time to include screening for neonatal alloimmune thrombocytopenia in the general antenatal health care programme?

A comprehensive screening and intervention program aimed to reduce morbidity and mortality of neonatal alloimmune thrombocytopenia (NAIT) has recently been carried out in Norway. HPA 1 typing was performed in 100,448 pregnant women. The HPA 1a negative women were screened for anti-HPA 1a antibodies. In immunized women, delivery was performed by Caesarean section 2-4 weeks prior to term with platelets from HPA 1a negative donors reserved for immediate transfusion in severely thrombocytopenic children. This screening and intervention program seemed to reduce the number of cases of severe NAIT-related complications to approximately one fourth. An accompanying health economic analysis seems to indicate that it is possible to establish an antenatal screening programme for NAIT that is cost effective. The Directorate for Health and Social Affairs is now considering if antenatal screening for NAIT should be included in the general antenatal health care programme in Norway.