Erythroblastosis Fetalis, also known as Hemolytic Disease of the Newborn, is a medical condition where there is a breakdown of red blood cells in a fetus due to an incompatibility between mother and baby blood types. There are various synonyms used for Erythroblastosis Fetalis such as Hemolytic Anemia of the Newborn, Rh Disease, Rh Incompatibility, and Alloimmune Hemolytic Anemia. These synonyms describe the same condition and its symptoms, which include anemia, jaundice, and liver and spleen enlargement in the newborn. Erythroblastosis Fetalis can be prevented and treated with proper medical care, including monitoring the mother's blood type and administering appropriate vaccines and antibodies to the baby.