ABO hemolysis refers to the destruction of red blood cells by lysis due to antigen-antibody reaction caused by blood group incompatibility. There are two types of ABO hemolysis in clinical practice. The first is a case of ABO hemolysis due to wrong blood type during blood transfusion, for example, if a patient with O blood type receives A blood, the anti-A antibody in O blood may combine with the A antigen in A blood, leading to red blood cell lysis and destruction. The second type is neonatal ABO hemolysis, also known as maternal-infant incompatibility ABO hemolysis, which commonly occurs when the mother has type O blood and the fetus has type A or B blood. This is because during pregnancy, the fetal red blood cells enter the mother’s body, causing her to produce anti-A antibodies or anti-B antibodies, which may enter the fetus during delivery and cause neonatal ABO hemolysis.