Neonatal haemolytic disease is defined as homozygous immune haemolysis due to maternal and child blood group incompatibility, caused by the destruction of fetal or new baby red blood cells created by maternal immunoglobulin IgG antibodies.
ABO haemolytic disease is the most common, accounting for 85.3% of cases, while Rh haemolytic disease is less common, accounting for 14.6% of cases.
The severity of symptoms is consistent with the degree of haemolysis, with the main manifestations being jaundice, anaemia, rising reticulocytes and, in severe cases, foetal oedema. Most ABO haemolytic disease is relatively mild, while Rh haemolytic disease has more severe symptoms, which may manifest as foetal oedema, hepatosplenomegaly and heart failure in addition to the above symptoms, and may result in stillbirth in severe cases, or may cause sequelae such as cerebral palsy, mental retardation, or even death after birth.