Abstract:

Objective     To analyze the RhD isoimmunization state of 304 RhD-negative pregnant and lying-in women, explore factors which affect production of the antiD antibody in them, and set up a correct prenatal testing method for RhD haemolytic disease of the fetus and newborn. Methods   ABO and RhD blood types of pregnant and lyingin women and their husbands were identified by the standard serological method. For RhD-negative women, the D antigen was further tested with the indirect antiglobulin test to exclude or confirm weak D or partial D types. The RhC, c, E and e antigens were typed in all RhD-negative women and their husbands. The irregular antibody was screened in all RhD-negative women, and if the result was positive, the specificity and titer of the antibody were determined. At the same time, if phenotypes of the RhD-negative women with the anti-D antibody were Del type or not was determined with the PCR-SSP method.  Results     Among 3,975 pregnant and lying-in women, 304 were confirmed to be RhD-negative, of whom 29  produced the anti-D antibody; 24 carried compatible ABO antigens with their husbands(82.76%); 5 carried incompatible ABO antigens with their husbands(17.24%) . The production rate of the RhD antibody in D-negative pregnant and lyingin women was 9.54% (29/304) . All 29 RhD-negative women with anti-D were excluded from carrying the Del phenotype with the molecular biological method. Conclusions     RhD isoimmunization is affected by many factors. Pregnant women with the Del type seldom produce the anti-D antibody. The anti-D level should be timely and regularly tested among pregnant women. For women who have produced the anti-D antibody,  the antibody level should be closely detected during pregnancy, which will  provide evidence for clinical treatment.

Key words: Rh blood group; RhDnegativity; RhD isoimmunization; AntiD antibody; Haemolytic disease of the fetus and newborn