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.
The perinatal effects of maternal Rh alloimmunization are now referred to as hemolytic disease of the fetus and newborn, and fetal manifestations of the disease are more appreciated with newer technologies such as cordocentesis and fetal ultrasonography.