[Hemolytic disease of the newborn due to ABO incompatibility (author's transl)].

Up to now, the exact diagnosis of ABO hemolytic disease of the newborn cannot be made either clinically or serologically. Affected babies are almost all either group A or group B from mothers of group O. In contrast to Rh hemolytic disease the immunological findings do not correlate well with the severity of the clinical course. Sometimes, it is impossible to differentiate between ABO hemolytic disease and non-antibody mediated hyperbilirubinemia. Pathogenetic aspects are discussed which may explain the differences between ABO and Rh hemolytic disease of the newborn. Aids to immunological and clinical diagnosis are given. Ante-natal treatment is not necessary. Indications for and technique of phototherapy and exchange transfusion are presented. Early application of these therapeutical methods prevents bilirubin encephalopathy, kernicterus with subsequent death or development of severe neurological sequelae.