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.
Genetics. Although the Rh antibody was and still is the most common cause of severe hemolytic disease of the newborn, other alloimmune antibodies belonging to Kell (K and k), Duffy (Fya), Kidd (Jka and Jkb), and MNSs (M, N, S, and s) systems do cause severe hemolytic disease of the newborn.