juxtaposition (plural juxtapositions) 1  The nearness of objects with little or no delimiter. 2  The extra emphasis given to a comparison when the contrasted objects are close together.
Hemolytic disease of the newborn (HDN), also known as alloimmune HDN or erythroblastosis fetalis, is a potentially fatal alloimmune condition where fetal red blood cells are destroyed by transplacentally acquired maternal antibodies. RhD is the most common offending paternal antigen.
Clinical of red cell antibodies in blood bank depend on whether they can cause in vivo hemolysis, which in turn will cause transfusion reactions or hemolytic disease of the newborn. 1  IgG will frequently cause in vivo hemolysis due to antibody coating the red blood cells. 2  IgM, with a few important exceptions, usually does NOT cause in vivo hemolysis.