Blood Group Antigens Phenotype Frequencies among Pregnant Women in Sokoto State, Nigeria

Background: Blood group antigens have been used to evaluate ethnic diversity of human populations and had been related to predisposing individuals to some diseases or may protect individuals against some diseases. They also play the most important role in success of pregnancy and blood transfusion. 
Aim: The aim is to determine the frequencies of some blood group antigens phenotype among pregnant women. 
Materials and Methods: The study is a cross sectional study   conducted in the department of obstetrics and gynaecology, antenatal clinic in Usmanu Danfodiyo Teaching Hospital Sokoto, from January 2020 to September 2020. This research included 1250 consecutively -recruited pregnant women on their first antenatal visit. The blood grouping were determined using standard tube techniques for ABO, MNSs, Duffy and Kidd antigens while column agglutination card was used for Rh C, E, c, e and Kell was utilized. 
Results: The sociodemographic characteristics revealed that the age range of the subject was 17-48 years .where majority were within the age between 21-30 years (61.3%). Majority of the pregnant women had their first antenatal visit during second trimester of their pregnancy (59.7%). 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% and 90.2% were RhD, RhC, RhE, Rhc and Rhe positive respectively. The prevalence of M, S and s positive were 75.5%, 31.4% and 63.3% respectively. Among the subjects studied, 97.6% were Kell positive while 2.4% were kell negative. The prevalence of Duffy a and b antigen were 1.1% and 0.5% respectively and the prevalence of Kidd a and b phenotype positive were 15.9% and 21.7% respectively. 
Conclusion: The pattern of distribution of ABO, Rh, MSs, Duffy and Kidd blood groups antigens among pregnant women in Sokoto was in agreement with other populations while that of Kell blood group antigen is at variance with other population particularly among Caucasians. Data derived from this study will help policy makers make evidenced –based decisions on management of HDFN.