[Severe form of neonatal hemolytic disease by anti-Vel allo-immunization].

Background: Routine detection of maternal sensitization during pregnancy sometimes reveals alloimmunization by exceptional antigens.

Case Report: A first pregnancy was complicated by a severe post-partum anemia in the mother, that required a blood transfusion. Irregular agglutinins were detected during the first trimester of a second pregnancy, for which the father was different from the first. The specific antibody was not identified at that time. The newborn, born at a gestational age of 39 weeks, developed severe jaundice at 3 hours of life, with hemolytic disease, anemia and hepatomegaly. Therapy included two transfusions of packed, washed red cells obtained from the mother on days 7 and 25. Immunologic tests showed that the hemolytic disease of this newborn was due to an anti-Vel alloimmunization.

Conclusion: Antibodies detected during the pregnancy must be identified in order to manage properly any perinatal problems due to rare antibodies.