The Distribution of the ABO and Rh ‘D’ Blood Groups among Pregnant Women in Rivers State, Nigeria: A Nine-Year Retrospective Study

Abstract

Introduction: The ABO and Rh blood groups are the most clinically relevant blood groups in transfusion medicine. Pregnancy could be associated with complications and may require blood transfusion. Aims: This study aimed to determine the distribution of ABO and Rh D blood groups among pregnant women initiating antenatal care in Rivers State, Nigeria. Method: This was a retrospective descriptive study of pregnant women attending antenatal clinic at the Rivers State University Teaching Hospital from 1st January 2015 – 31st December 2023. A total of 16,605 pregnant women seen during the study period were included in the study. The results were retrieved from the antenatal booking registers in our facility. The data were computed into Microsoft Excel 2016 spreadsheet and analyzed with the IBM SPSS Version 26. The result was presented in tables and figures. Result: A total of 16605 pregnant women were seen at the antenatal clinic of RSUTH between 2015 and 2023. The mean age was 31.61 years, with age range of 15-58 years. The 26 to 35 years age group comprised 67.2% of the participants while participants aged more than 45 years comprised 0.4%. The majority of participants had an O blood group (n = 9789, 58.95%), followed by the A blood group (n = 3791, 22.83%) while the least was the AB blood group (n = 386, 2.32%). Regarding the Rh system, the prevalence of the Rh D negative type was (n = 774, 4.66%) while the Rh D Positive type was (n = 15,831, 95.3%). When both the ABO and the Rh blood groups are combined, the most prevalent was the blood group O Rh D Positive (n = 15,831, 95.3%) followed by Blood group A Rh positive (n = 3633, 21.9%) while the least was AB Rh negative (n = 10, 0.1 %). Conclusion: Pregnancy is a physiologic condition that could be associated with complications requiring blood transfusion services. The most prevalent blood group in the ABO system was blood group O followed by group A, B and AB. In the Rh system, Rh D was the most prevalent.Determining the blood group of the pregnant woman is important in eliminating the critical consequences of ABO and Rh incompatibility. Our finding will be very useful in management of cases of obstetric haemorrhage and cases of feto-maternal incompatibility.