Clinical study of the relationship between prenatal antibody titer and hemolytic disease of newborn

Hemolytic disease of newborn (HDN) is caused by the emergence of inappropriate antibodies against fetal blood antigens, which includes ABO and Rh blood group incompatibility. This study investigated the association between prenatal blood group antibody titer and HDN to provide a theoretic basis for clinical practice. ABO and Rh blood group of 7894 pregnant women and their husbands were screened. Patients with blood group incompatibility were chosen for blood antibody test and antibody titer analysis. Umbilical cord blood was tested for HDN. Antibody titers were measured by ELISA and western blot. The association between prenatal blood antibody titer and HDN were analyzed. There were 4742 cases (60.1%) of ABO-incompatible couples, 2574 cases with anti-A/B antibody titer ≥ 64 (54.3%), including AB/O, A/O and B/O. Sixty cases showed fetal-maternal blood group incompatibility (ABO/ HDN), suggesting a significant positive correlation between mother blood group antibodies and fetal cord blood bilirubin > 80 μmol/L. There were 60 Rh-incompatible couples (0.91%) including 8 cases who showed antibodies positive with increased anti-E and D titers. RH-HDN was confirmed by umbilical blood group test. Logistic regression analyses identified Rh blood group incompatibility (OR = 1.56), anti-E positive (OR = 2.15), anti-D positive (OR = 1.32), anti-A/B IgG titer ≥ 64 (OR = 1.63) as risk factors for HDN (P < 0.05). Prenatal blood group antibodies test can predict the relationship between blood group antibody titer and HDN by tracking anti-A/B antibody titers, and thereby prevent the occurrence of fetal RH-HDN.