Distribution of ABO, Rh D blood groups and haemoglobin phenotypes among antenatal clinic attendees in Federal Medical Centre Nguru, Nigeria

Abstract

Background: Blood groups antigens and haemoglobin genotypes are genetically controlled and are specific to an individual. Blood groups remain unchanged throughout life and are important to avoid fatal blood transfusion reactions. Haemoglobin phenotypes are necessary for the laboratory detection of most common clinically important haemoglobin variants as it determines the transfusion demand which is necessary for setting up and planning of a blood transfusion unit. Objectives: To determine the distribution of ABO, Rh D blood groups and haemoglobin phenotypes in pregnant women attending antenatal care at the Federal Medical Centre (FMC)
Nguru, Yobe state, North-Eastern Nigeria. Methods: A retrospective chart analysis of 5,519 records of pregnant women who were sequentially booked in antenatal care clinic at the permanent site of FMC Nguru, over a 2 year period, from January 2009 to December 2010. The ABO and Rh D blood groups and haemoglobin electrophoretic pattern were obtained from the haematology antenatal record register and analyzed. Results: Overall, a total of 5474 and 5508 records were analyzed for ABO/Rh D blood groups and haemoglobin electrophoretic pattern respectively. The mean age of the study subjects was 24.6 ± 5.84 years and a mean packed cell volume of 32.6 ±4.51%. Blood group O was commonest accounting for 49.2% followed by blood group B (26.0%) and A (21.3%) while blood group AB had the lowest distribution of 3.5% (O>B>A>AB). Rhesus Rh D positivity (RhD/RhDd) rate was 95.4% while RhD negativity (Rhdd) accounted for 4.6%. Five haemoglobin phenotypes (electrophoretic pattern) were recorded in the order of HbAA (76.12%) > HbAS (23.4%) > HbAC (0.27%) > HbSS (0.16%) > HbSC (0.05%). HbAA and HbAS occurred more frequently than other haemoglobin variants. Conclusion: Although our study included only pregnant women, the finding of this study is consistent with the previously published data in Nigeria. This study will serve as a baseline data for FMC Nguru to determine and formulate an effective and efficient blood transfusion services amongst pregnant women and also it will serve as a guide for premarital counselling in this community.