RESUMO
<p><b>OBJECTIVE</b>To investigate the RHD zygosity of Rh(D)-positive Chinese Hans in order to study the mother-fetus Rh isoimmunization prophylaxis.</p><p><b>METHODS</b>Rh(D) blood group of 31 115 donors were serotyped, and the RHD zygosities were analyzed, or determined through a PCR method for 3628 donors of Rh(D)-positive individuals.</p><p><b>RESULTS</b>Among the 31 115 donors, 99 were tested Rh(D)-negative by indirect antiglobulin test (IAT) (0.318%). The d frequency was 0.056 41, D was 0.943 59, and Dd heterozygosity was 0.106 45 (10.6%). However the rate was 0.090 32 (about 9.0%) after excluding DEL (IAT-negative). For the 3628 PCR tested donors, 3383 were DD (93.2%), 245 were Dd (6.8%). After excluding nonfunctional RHD alleles, 7.4% of the donors were carrying one functional RHD. It showed that an Rh(D)-negative Chinese Han woman gives an Rh(D)-negative child at a rate of 3.7%-4.5% when her husband is Rh(D)-positive.</p><p><b>CONCLUSION</b>Fetus Rh(D) genotyping may be unnecessary for Chinese Hans if invasive operation was needed for prenatal diagnosis. The Rh prophylaxis could be chosen assuming an Rh(D)-positive fetus.</p>