Rhesus incompatibility amongst child-bearing women in Ile-Ife, South Western Nigeria

Abstract

Background: Rhesus (Rh) isoimmunisation is a recognized cause of perinatal mortality and is also a risk factor for neonatal jaundice. It occurs exclusively in parous RhD negative women with at least one prior pregnancy or in women with previous transfusion of incompatible Rh blood irrespective of their parity. Record on the prevalence of Rh negative pregnant women and the incidence and significance of isoimmunisation on pregnancies is sparse in our setting. This study attempts to provide an insight report on pregnancy outcome in Rh negative Nigerian women. Materials and Methods: The blood bank record of all pregnant women from January 2003 to December 2007 was reviewed for their ABO and Rh blood group. All those that were Rh negative and had their deliveries at the Obafemi Awolowo University Teaching hospitals Complex, Ile-Ife had their clinical case notes reviewed for the outcome of their pregnancies. Results: A total of 2159 pregnant women had their blood group screened, 168 (7.8%) were Rh negative. Of those with complete clinical data, 72% had blood group O while none had blood group AB. Only 44.4% and 66.7% of the husbands and babies’ blood group respectively were documented; 8.3% of the babies were ABO compatible with their mothers. Only 16.7% of the babies appeared to have Rh incompatibility with clinical jaundice although all had negative serial indirect Coomb’ test which was done in 55.6% of cases for antibody titre estimation. The mean total and unconjugated bilirubin levels of 64µmol and 54µmol respectively. None had phototherapy or blood transfusion. The mean birth weight and haematocrit were 3.1kg and 45.1% respectively. All deliveries were un-eventful with administration of anti-D immunoglobulin (1500 IU statum dose) documented in 50% of cases given within 72 hours of delivery. Conclusion: The prevalence of Rh negativity amongst pregnant women from this study is 7.8%, suggesting that Rh negative blood group is not uncommon in our population. The neonate with incompatible group had mild haemolytic disease indicating good pregnancy outcome. However, adequate counselling is still required in our child-bearing women to prevent morbidity from Rh incompatibility.