Clinically, a maternal serum antibody titer threshold of 1:64 is typically regarded as critical; titers at or above this level suggest a potential risk of ABO-HDFN in infants.[16] Nonetheless, relying solely on prenatal detection of maternal serum IgG anti-A(B) antibody titers to predict perinatal hemolysis presents certain limitations. Here, ABO is linked to hemolysis.