Seroprevalence of Rhesus antigens, genotype distribution and its relations with ABO groups among Pregnant Women in University of Calabar, Calabar, Nigeria

Abstract

The Rhesus blood group system consists of six genes: Cc, Dd, Ee. At least 36 Rhesus genotypes are possible based on the combinations of genes that can be inherited (Agarwal ef al., 2014). This study is aimed at providing information on the seroprevalence of Rhesus genotype distribution and its association with ABO group among pregnant women in University of Calabar Teaching Hospital, Calabar Nigeria. A descriptive cross-sectional study comprising of 400 pregnant women who gave their informed consent were recruited. Whole blood and serum were collected and used respectively for the study. Rhesus blood group was analysed using a commercially prepared reagent. Antibody screening was performed using standard cells. Antibody identification was done using panel cells. Frequency, percentage and chi-squared statistical tools were used. Most of the pregnant women were aged 16 -— 36 years and primegravidae constituted majority of subjects recorded in this study. The prevalence of Rhesus positive and Negative was 95% and 5% respectively. Seropositive was anti-C 88 (22.0%), anti-c 394 (98.5%), anti-E 106(26.5%), and anti-e 394 (98.5%), while seronegative was anti-C 312(78.0%), anti-c 6(1.5%), anti-E 294(73.5%), anti-e 6(1.5%) respectively. Percentage distribution of Rhesus phenotype among the pregnant women was found to be R'R” (51.50%) followed by R’R’ (22%) and R'R® (17.5%), while the least were r'r, R’R’, R’R', ryry and R'R', which recorded 0.50%. The most prevalent possible genotype was cDe/cD while CdE/CdE had the least genotype found in blood group A. The negative Rhesus genotype cde/cde (rr) was found in 2.5% of the studied population and found in blood group O alone. Rhesus phenotyping should be included as routine screening test and all pregnant women should be screened irrespective of their Rhesus status.