Heamolytic disease of the newborn

Haemolytic disease of the newborn (Erythroblastosis fetalis) is a disease in which Rhesus incompatibility between a mother and a foetus causes the mother's immune system to attack and destroy the foetal RBCs. This results in severe haemolytic anaemia and the associated issues of intravascular coagulation, damage to the heart and lungs, jaundice and swelling of theliver and spleen in the foetus.

Cause

Haemolytic disease of the newborn occurs, when Rh positive foetal RBCs cross the placenta and enter the Rh negative mother’s bloodstream. The Rhesus antigens expressed on the foetal RBCs are recognised as foreign to the maternal immune system and IgG antibodies are raised against them. These maternal anti-Rh IgGs are capable of crossing the placenta and coating the foetal RBCs, enabling phagocytosis by white blood cells.