ABO, Rh, and Kell Blood Group Antigen Frequencies among Pregnant Women in Sokoto, Nigeria.

Background: Blood group antigens have been used to evaluate ethnic diversity of human populations and they also play most important roles in pregnancy and blood transfusion. Knowledge of antigen frequencies is important to assess the risk of alloimmunization and to guide the probability of finding antigen-negative donor blood. This study was aimed at determining the frequencies of ABO, Rh and Kell blood group antigens phenotype among pregnant women. Materials and Methods: The study was cross sectional in nature conducted among 1,250 consecutively recruited pregnant women in the department of Obstetrics and Gynaecology, antenatal clinic in Sokoto from January 2020 to September 2020. The blood grouping were determined using standard tube techniques for ABO while column agglutination card was used for Rh C, E, c, e and Kell blood groups. The data were collected, and calculations were done to determine the frequencies of ABO, Rh, and Kell blood group antigens and chi square was used to determine statistical significance . Results: The distribution of the ABO blood group revealed that 48.5% were group O, 27.3% were group B, 19.4% were group A and 4.8% were group AB. Out the subjects investigated, 93.1%, 30.2%, 24.6% , 90.2% and 97.6%were RhD, RhC, RhE, Rhc and Rhe positive respectively while 2.4% were Kell positive while 97.6% were Kell negative. ABO antigens has statistically significant correlation with Kell antigens. Conclusion: There is phenotypic variability of ABO and Rh blood group antigens with low prevalence of Kell antigen that has statistical relationship with ABO antigen. Incorporation of blood group phenotyping as premarital screening may reduce the prevalence of alloantibody formation.