Frequencies of maternal red blood cell alloantibodies in Port Harcourt, Nigeria

Background: Alloantibodies of clinical importance can cause transfusion reactions or hemolytic disease of the fetus and newborn (HDFN). The frequencies of these antibodies have not been reported in our locality. Aims: To determine the frequency of occurrence of alloantibodies among pregnant women in Port Harcourt, Nigeria. Settings and Design: This is a prospective study, which was carried out in the Braithwaite Memorial Specialist Hospital, Port Harcourt, Nigeria. Materials and Methods: Screening and identification of red blood cell alloantibodies was done on the sera of 500 pregnant women using the DiaMed, DiaCell, and DiaPanel reagents (Cressier, Switzerland). ABO and Rh blood groups were done using antisera bought from Biotec (Ipswich, UK). Results: Alloantibodies were identified in the serum of 17 of the 500 (3.4%) pregnant women. The specificity of the antibodies was as follows: anti-C 6 (1.2%), anti-E 3 (0.6%), anti-Jsb 3 (0.6%), and anti-K 5 (1.0%). No anti-D was identified despite 8.6% of the study population being Rhesus D (Rh D) negative. The distribution of the antibodies was found to be independent of the blood groups of the participants (x 2 = 4.050, P = 0.670). Blood group O constituted the highest percentage (48.0%). Conclusion: This study has identified the presence of non-Rh D antibodies to the proportion of 3.4%. Rh D antibody was absent in this population irrespective of the relatively high percentage of Rh D negative women. There is a need to determine the actual risk these antibodies may pose to the antenatal women and to include antibody screening and identification in routine antenatal care.