Fetal and Neonatal Alloimmune Thrombocytopenia: Advances in Laboratory Diagnosis and Management

Abstract

Fetal and neonatal alloimmune thrombocytopenia (F/NAIT), caused by fetomaternal mismatch for human platelet (PLT) alloantigens (HPAs), is the commonest cause of severe thrombocytopenia in term neonates and is analogous to the fetal/neonatal anaemia caused by haemolytic disease of the newborn (HDN). The most feared complication of this syndrome is the occurrence of intracranial hemorrhage leading to death or neurological sequels. With advances in laboratory diagnosis and management of the index case and of pregnancies at risk, the prognosis of affected infants has improved. The study of F/NAIT have drawn attention to the fact that the first affected fetus/neonate in a family is only recognized after bleeding has occurred and this has raised the question of whether routine screening for F/NAIT would be advantageous. Further research must focus on the mechanisms of maternal sensitization and development of specific therapy.