Hemolytic Disease of the Fetus and Neonate (Erythroblastosis Fetalis; Rh Incompatibility) By Antonette T Dulay, MD, Main Line Health System Reviewed / Revised Oct 2022 View Patient Education Pathophysiology Diagnosis Treatment Prevention Key Points Hemolytic disease of the fetus and neonate is hemolytic anemia in the fetus (or neonate, as erythroblastosis neonatorum) caused by transplacental transmission of maternal antibodies to fetal red blood cells.