Significance of blood group antibody titer detection in prenatal diagnosis

Objective:To study the distribution of abnormal IgG antibody A(B) or antibody D in pregnant women and explore the relationship between hemolytic disease of newborn (HDN) and the titers of IgG antibodies in pregnant women,in order to provide an important experimental basis for HDN prevention and treatment. Methods:The titers of IgG antibody A (B) and antibody D were measured in 1316 pregnant women with blood type O and 64 with Rh(D) negative blood type using polybrene method. The three hemolytic tests were designed to diagnose HDN in the newborn whose mother had the risk of HDN before delivery using microcolumn gel technique. Results:① Among 1316 maternal sera with blood type O,antibody A and antibody B were 802 cases and 744 cases respectively. Titer of IgG antibody A more than 1∶64 were found in 129 cases with the abnormal detection rate of 16.1% in the total anti-A,whereas titer of IgG antibody B were 135 cases with the abnormal detection rate of 18.1% in the total anti-B. Among 89 newborns whose mother with blood type O were found the titer of IgG antibody A(B) more than 1∶64,22 suffered from HDN (24.7%); ②In 64 pregnant women with Rh(D) negative blood type,antibody D were found in 5 cases (7.8%),and 3 newborns developed Rh-HDN. Conclusion:① The incidence of neonatal HDN increased along with the increasing of the mother's IgG antibody levels. ② For the Rh (D) negative pregnant women,IgG anti-D titer was positively related to gravidity.