Hemolysis of the newborn does not necessarily occur in the offspring of an O blood type and an AB blood type.
If the father has type O blood and the mother has type AB blood, the child may have type A or B blood, in which case there are no antibodies against the fetus in the mother’s body, and therefore ABO hemolysis does not usually occur.
If the father is AB and the mother is O, then the mother has antibodies against the fetus, which may bind to the fetus’ red blood cells and hemolysis of the newborn may occur.
Therefore, it is recommended to undergo standardized obstetrical examination during pregnancy, and if the fetus is at risk of hemolysis, the elevated bilirubin and postnatal jaundice of the fetus should be closely monitored, and the symptoms should be controlled and treated.