The contemporary management of haemolytic disease of the fetus and newborn.

Haemolytic disease of the fetus and newborn (HDFN) remains an important cause of perinatal mortality and morbidity. The pathogenesis underlying this condition is maternal red cell alloimmunization, with immunoglobulin G (IgG) antibodies produced in response to 'non-self', inherited paternal antigens expressed upon fetal erythrocytes. The IgG antibodies cross the placenta into the fetal circulation causing red cell destruction and fetal anaemia. Intrauterine transfusion (IUT) remains the cornerstone therapy with fetal survival rates up to 97%, but it is an invasive, technically challenging surgical procedure performed at specialized medical centres. The procedure-related risk of IUTs is increased at gestational age before 24 weeks. This has stimulated interest in maternal medical therapies that attenuate the risk of severe fetal anaemia, increase the gestational age of first IUTs, and reduce perinatal mortality and morbidity. This review summarizes current evidence for such treatments: intravenous immunoglobulin therapy and neonatal fragment crystallizable (Fc) receptor blockade for managing severe HDFN.