Hemolysis may occur in children with blood types O and AB, but not absolutely. If the mother has blood type O and the father has blood type AB, the child’s blood type may be A, B or AB. The child’s red blood cells enter the mother’s body and produce anti-A and or anti-B antibodies, which are then transported to the fetus through the placenta, and hemolysis may occur, but it is not absolutely likely to happen. After the birth of the child must pay close attention to the jaundice index, if the jaundice appears early, the degree of heavy, we must be highly vigilant whether the occurrence of hemolysis, early detection and early treatment can be very good cure, if the occurrence of hemolysis is not paid attention to, may occur serious consequences. If the father is type O and the mother is type AB, the child will not have hemolysis.