hemolytic disease of the fetus and newborn, alloimmune hemolytic anemia caused by placental transfer of IgG blood group antibodies from an immunized mother to the fetus, whose red cells carry an antigen inherited from the father. Hemolysis of fetal red cells can cause severe anemia, jaundice, and enlargement of the liver and spleen, which, without intervention, can lead to hypoxia, cardiac failure, generalized edema, respiratory distress, and death.
