Study on the relationship between the level of blood type antibody IgG of pregnant women with O type and HDN

Objective In order to understand the relationship between the level of blood type antibody IgG of pregnant women with O type and hemolytic disease of newborn(HDN). Methods 2 814 cases pregnant women's and their husbannds's ABO and Rh(D) blood types were detected. Prenatal immunohematological tests including ABO and Rh(D) blood types. antiA(B) IgG titer assay, irregular antibody screening and specific determination were conducted to those pregnant women whose husbands were not O type. AntiD IgG was also detected for those Rh(D)negative cases. Meanwhile, ABO blood types, Coombs test, free antibody and antibody release test were done for those 212 newborns whose mothers were at the risk of prenatal HDN so that the relationship between pregnant women prenatal IgG level and HDN was understood. Results The cases of Oblood type pregnant women whose husbands were not O type were 767, accounting for 27%(767/2 841) the rate of Rhnegative was 0.32%(9/2 841). The rate of Rhnegative who generated antiD made up 33.3%(3/9). The cases of antiA(B) IgG titer64 in all the imcompatible blood group pairs were 212, accounting for 27.6%(212/767). Of 212 pregnant women risking themselves of prenatal HDN, 36 newborns were ill with HDN, accounting for 17%. Conclusion The relationship between the level of IgG blood type antibody and the incidence of HDN was in proportion.