Abstract: Objective To study the value of serum IgG anti-A/B titer score of pregnant women with blood type O for predicting the hemolytic disease of newborn (HDN). Methods 45 blood type O pregnant women with high IgG antibody titer were selected as the research object. The IgG titer of the mother was measured by anti-human globulin test carried out by traditional tubing test. At the same time, the score of each tube were measured according to the intensity of agglutination. To obtain the antibody titer scores of the tested samples, add up the scores of the tubes. The correlations between the IgG antibody titer score of pregnant women and the possibility of HDN of newborns were analyzed. Results Of the 45 newborns, 27 were diagnosed as HDN. With the serum antibody titer of pregnant women increasing, the prevalence of HDN shows an upward trend, but the difference between different antibody titer groups was not statistically significant. There was a statistically significant correlation between the titer score and the incidence of HDN, and the correlation coefficient was -0.665. Conclusion Compared to antibody titer, the titer score of pregnant mothers is more closely related to the incidence rate of HDN of newborn. The IgG antibody titer score of pregnant women has more clinical significance in predicting the HDN of hemolytic disease.

Key words: Pregnant women, Blood group antibody, Hemolytic disease of the newborn, (HDN), IgG antibody titer, IgG antibody titer score