Generally, if the mother’s blood type is O and the husband’s blood type is A, B or AB, anti-A or anti-B antibodies will be produced in the mother’s blood. In the next pregnancy, if the fetus has blood type A, B or AB, this is known as maternal and infant ABO blood group incompatibility, but only a small percentage of fetuses develop hemolysis and show symptoms of hemolysis (jaundice) after birth. Maternal and child ABO disorders can also occur in the first child because the mother is exposed to some blood group-like substances in nature and develops anti-A and anti-B antibodies when she is not pregnant. Screening for maternal and child ABO blood group incompatibility is not routinely recommended during prenatal screening for the following reasons: 1. There is no direct relationship between antibody levels in the mother’s blood and neonatal ABO hemolysis, so even if anti-A anti-B antibodies are found in the pregnant woman’s blood, it is not advocated to report the results. 2. Even if fetal hemolysis is suspected during pregnancy, there is no evidence-based medical evidence that drug therapy is effective. 3, ABO hemolysis rarely has serious consequences, because after anti-A and anti-B antibodies enter the fetus, they bind to various different fetal cells, and the number of antibodies that actually bind to fetal red blood cells is relatively small. In addition, the A and B antigens on the surface of fetal red blood cells are not fully developed, so there are fewer antigenic sites that can bind with antibodies. The diagnosis of ABO hemolysis depends mainly on the jaundice of the newborn on the first day after birth, and it is very rare that hemolysis is severe enough to require blood transfusion therapy. Since there is no direct relationship between the level of antibodies in the mother’s blood and ABO hemolysis in newborns, and there are no drugs that can be used to effectively treat it, and there are no serious consequences, why do we need to screen for it? Why do we need to increase the anxiety of the mother-to-be? The actual fact is that you will be able to get a good deal on your own. Except for Rh blood type incompatibility, which can lead to serious fetal complications or even stillbirth.