Prevalence of Rhesus C and D Alloantibodies among Rhesus-Negative Women of Child Bearing Age at a Tertiary Hospital in South-West Nigeria

Background: A major cause of hemolytic disease of the fetus and newborn (HDFN) is an incompatibility of the Rhesus (Rh) blood group between the mother and fetus. Aim: To determine the prevalence of Rh c and D alloantibodies among Rh-negative women of childbearing age (18-49 years). We conducted a cross-sectional study among women who attended the antenatal, gynecology and blood donor clinics at a Tertiary Hospital in South-West Nigeria from January to August 2019. Serological typing of Rh c and D was done manually with the tube test using anti-c and anti-D antisera, while indirect antiglobulin test was then performed to screen for Rh antibodies. Subjects and Methods: Data was analyzed using Stata 16.1 software; Categorical data was summarized using frequency and percentages while continuous variables were described using the mean and standard deviation or median and interquartile range. Pearson's Chi-square (or Fisher's exact) test was used to test for association between categorical variables and Rh status. P values of <= 0.05 were assumed to be statistically significant. Results: A total of 700 consenting women, comprising 505 pregnant (72.1%) and 195 non-pregnant (27.9%) women were recruited into this study. The mean age was 30.7 +/- 4.9 years. All (100%) participants were Rhc positive while 641 (91.6%) were RhD positive and 59 (8.4%) were RhD negative. All 59 RhD negative subjects tested negative for anti-D. There was no statistically significant difference between proportion of RhD-negative women who had a jaundiced baby and the proportion of RhD-positive women who had a jaundiced baby (15.6% vs. 18.6%, P = 0.540). Conclusions: This study did not identify any Rhc and D alloantibodies in the study population suggesting there is a low risk of alloimmunization and HDFN due to anti-Rhc and D in this population.