Whether the child born with type A and type O blood will be hemolyzed is divided into the following cases: 1. If the mother is type A and the father is type O, the baby born may be type O or type A blood. This situation will generally not lead to hemolysis as long as the mother is type A and the baby born is type O or type A. 2. If the mother is type O and the father is type A, the child born is likewise of two kinds, i.e., it is possible to be type O or type A. If the baby is type O blood, hemolysis will not usually occur. If the blood type is A and the mother is O, there is a possibility that ABO blood type incompatibility hemolysis will occur. Therefore, it is not possible to directly answer whether hemolysis will occur in a child born with blood type A and blood type O. Its determination depends on the blood type of the child and the mother. In general, it is possible to check the mother’s antibody titer during pregnancy, and if the antibody titer is very high, it may lead to hemolysis. It is important to go for intervention as early as possible after the baby is born, including the use of some gammaglobulin, etc. It is also important to monitor the child’s condition, and if the jaundice is very severe, it should be treated promptly and early. If hemolysis occurs in the child, it should also be treated actively. Especially in severe ABO hemolysis, the child’s bilirubin may be very high and progress quickly, which can lead to nuclear jaundice, or bilirubin encephalopathy. Therefore, severe ABO-mismatched hemolysis requires early and aggressive intervention and treatment, including blue light irradiation, blood exchange, and gammaglobulin.