To study the frequency of haemolytic disease of newborn due to abo maternal-fetal incompatibility

Background:  Hemolytic disease of newborn is characterized by the presence of IgG antibodies in maternal circulation, which causes hemolysis in the fetus by crossing the placenta and sensitizing red cells for destruction by macrophages in the fetal spleen with consequent hyperbilirubinemia.
Aim:  Present   study  was done to find out  Prevalence of  ABO HDN in our hospital .
Material and Methods: Sample were collected after fulfilling inclusion and exclusion criteria. Samples with significant hyperbilirubinemia with rising bilirubin level on the first day more than 18 mg/dl and reticulocytosis more than 5 along with peripheral smear showing  features of haemolysis with  spherocytes, schistocytes ,polychromasia were taken as positive cases .The following tests were performed on each satisfactory specimen: (1). Direct Coombs test,(2) ABO Rh (3), Hemoglobin, (4) plasma bilirubin, (5) examination of peripheral smear (6) reticulocyte count.
Results: In present study a total of    100 cases were studied and out of this 31% reported ABO HDN.  Out of 31 ABO incompatible neonates 22(70.97%) were males and 9(29.03%) were females. The percentage of O-A incompatible neonates were 17% , percentage of O-B incompatible neonates were 13%  and1%  belonged to O - AB group.
Conclusion: The  estimated risk of ABO HDN among non-group –O offspring of blood group O women is 31%. Early  identification of high risk neonates with ABO incompatibility, diagnosis and early intervention can reduce morbidity and mortality.