If the parents have the same blood type O, the child will not normally be hemolyzed. However, if the mother’s blood type is O and the father is type A, B, or AB. If the fetus has the same blood type as the mother, the fetus is not prone to blood group incompatibility, but if the fetus has the same blood type as the father, theoretically the mother may produce antibodies against the fetal red blood cells and enter the fetus through the placenta, resulting in the destruction of the fetal red blood cells and hemolysis. However, intrauterine hemolysis is relatively rare in clinical cases with ABO blood group incompatibility. No special treatment is needed during pregnancy, and the newborn should be tested for neonatal pathological jaundice and promptly seen by a pediatrician. Many pregnant women with O blood type are worried about the possibility of hemolysis in their newborns, but the clinical finding is that the incidence of ABO blood group incompatibility is about 20%, but only 5% of newborns actually have hemolysis.