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.
A French midwife was the first to report hemolytic disease of the newborn (HDN) in a set of twins in 1609. In 1932, Diamond and colleagues described the relationship among fetal hydrops, jaundice, anemia, and erythroblasts in the circulation, a condition later called erythroblastosis fetalis.