Hemolytic disease, also known as hemolytic disease of the newborn, is a homozygous immune hemolysis caused by mother-infant blood group incompatibility, and is only seen in the fetal and neonatal periods. There are usually ABO hemolysis and RH hemolysis. When the blood group antigens of fetal red blood cells are lacking in the mother, the fetal red blood cells enter the maternal circulation through the placenta, which can cause the mother to produce antibodies corresponding to the antigens of fetal red blood cells, and the antibodies will be circulated to the fetus through the placenta, which will act on the fetal red blood cells to sensitize them and lead to hemolysis. 1. ABO hemolysis: it mainly occurs when the mother is type O and the fetus is type A or B, and the mother and child have incompatible blood types. This type of blood group incompatibility is the most common. 40%~50% of ABO hemolytic disease occurs in the first child, the reason is: O-type mothers in the first child before pregnancy, has been subjected to natural A or B blood group substances (some plants, parasites, tetanus and diphtheria toxin, etc.) stimulation, the production of anti-A or anti-B antibodies. 2. Rh blood group incompatibility: i.e. the mother has Rh negative blood and the child has RH positive blood. rh blood group incompatibility causes intrauterine hemolysis. However, this situation often occurs in the second pregnancy. This is because there is no Rh blood group in nature and Rh antibodies can only be produced by stimulation of the Rh antigen in human red blood cells. It is recommended that once the diagnosis of hemolysis in infants is confirmed, it should be treated aggressively, and any abnormalities should be treated by a doctor in time to avoid delays.