What to Know about Neonatal Alloimmune Thrombocytopenia (NAIT) ?

Neonatal alloimmune thrombocytopenia (NAIT) is the most common cause of severe thrombocytopenia in full-term newborns. In the mother and fetus with incompatible platelet antigens, there is a risk of developing anti-platelet alloimmunization. It corresponds to Rhesus (Rh) alloimmunization in pathophysiology. These platelet alloantibodies pass trans-placentally into fetal circulation and cause fetal platelet destruction. Although its presentation may be isolated thrombocytopenia, some affected infants may suffer major hemorrhages, including intracranial hemorrhage (ICH), which may occur as early as 16 weeks of gestational age, and the first pregnancy may not be spared. Death or neurologic impairment occurs in up to 25% of the affected infants. NAIT is managed both ante- and postnatally. Postnatal management of NAIT depends upon the platelet count and the neonate's clinical condition. At the same time, antenatal management of NAIT aims to ameliorate fetal thrombocytopenia in subsequent pregnancies after diagnosis of NAIT in a previous pregnancy and thus prevent fetal and neonatal ICH.