Hemolysis will not occur if the mother has type O blood and the first-born fetus has type O blood. Hemolysis in newborns is often seen when the mother and fetus do not have the same blood type, the mother’s O blood type and the fetus’s O blood type, both of them have the same blood type, hemolysis will not occur. Normal people have two blood group classification systems, one is the ABO blood group system and the other is the Rh blood group system. For the ABO blood group, if the mother has blood type O and the fetus is type A or B, mild hemolysis of the newborn may occur. For Rh blood group, if the mother has Rh negative blood and the first fetus has Rh positive blood, neonatal hemolysis may occur if the second fetus has Rh positive blood. Neonatal hemolysis is mainly manifested by jaundice symptoms such as yellow skin staining, so it is important to seek prompt medical attention if neonatal hemolysis is suspected.