RESUMO
ABO iso-immunization is the most frequent haemolytic disease of the newborn. Treatment depends on the total serum bilirubin level, which may increase very rapidly in the first 48 hours of life in cases of haemolytic disease of the newborn. Phototherapy and, in severe cases, exchange transfusion are used to prevent hyperbilirubinaemic encephalopathy. Intravenous immunoglobulins [IVIG] are used to reduce exchange transfusion. Herein, we present a female newborn who was admitted to the NICU because of ABO immune haemolytic disease. After two courses of 1 g/kg of IVIG infusion, she developed necrotizing enterocolitis [NEC]. Administration of IVIG to newborns with significant hyperbilirubinaemia due to ABO haemolytic disease should be cautiously administered and followed for complications