FOETO-MATERNAL BLOOD GROUP INCOMPATIBILITY AND HAEMOLYTIC DISEASE OF THE NEWBORN IN ZARIA, NIGERIA

Abstract

Introduction: Foeto-maternal blood group incompatibility can lead to haemolytic
disease of the newborn by presenting in utero with anaemia, fluid retention, the severest
form as hydrops fetalis and post partum with anaemia and hyperbilirubinaemia which
may cause kernicterus.
Methods: A total of 127 consenting mothers with their 129 babies were studied. A
clinical examination, including Full Blood Count, Blood grouping of the following
systems; ABO, Rhesus, Kell, Kid, Duffy, MNSs were done. Direct and Indirect
antihuman globulin tests were carried out on the mothers and babies respectively.
Kleihauer-Betke’s test was done on maternal samples and serum bilirubin assay in baby
samples.
Results: Blood group O was the commonest in the ABO system in study population. In
the Rhesus system the commonest antigen present was c with 252 (98.44%) prevalence.
In the Kell system, all samples were negative for K antigen. In the Kidd system, Jka+ was
found in 7 (2.74%) and Jkb+ was positive in 5 (1.95%) of study population. The Duffy
antigen, Fya+ was positive in 2 (0.78%) and Fyb+ 1 (0.39%) of the study population. In the
MNSs system 100% of the study population are s-antigen positive. The Kleihauer
Betke’s test was positive in 73.2% of the mothers. The antihuman globulin test among
those with incompatibility was 10 (71.69%) and 14 (100%) in the babies and mothers
respectively. An incompatibility rate of 71 (55.04%) out of 129 mother-baby pairs in the
antigens studied. Antibody-A had the highest frequency (6/14), and anti-E in the Rhesus
system. The mean cord blood bilirubin levels of babies with incompatible and those
without was significantly different (P<0.001).
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Conclusion: The blood group O is the commonest ABO blood group among the study
population. The commonest Rh antigen is c which is similar to the pattern among the
immigrant Negroid population in England. The commonest antibody causing haemolytic
disease of the newborn in this environment was anti-A in the ABO system, while in the
Rh system anti-E was found. More than 50% of the study group had blood group
incompatibility 14 (10.9%) having evidence of HDN. This study showed a good
correlation between blood group distribution and prevalence of foeto-maternal blood
group incompatibility.