Final answer:
Hemolytic disease of the newborn (HDN) occurs when anti-Rh antibodies from an Rh-negative mother attack the Rh-positive red blood cells of her fetus, which is especially concerning in second or subsequent pregnancies. Treatment includes the use of Rho(D) immune globulin (RhoGAM) to prevent the mother's immune system from becoming sensitized to Rh-positive fetal blood cells and may involve transfusions to manage the condition.
Step-by-step explanation:
Hemolytic disease of the newborn (HDN), also known as erythroblastosis fetalis, is a condition primarily associated with incompatibility between the Rh factors of a mother and her fetus. This type II hypersensitivity reaction occurs when a Rh-negative mother, previously sensitized by Rh-positive fetal red blood cells, develops anti-Rh antibodies that can cross the placenta in subsequent pregnancies and target the fetus's Rh-positive red blood cells for destruction, leading to hemolysis. HDN tends to be a significant issue in second or subsequent pregnancies because only after the first pregnancy in which fetal and maternal blood mix does the mother begin to produce anti-Rh antibodies. To prevent this immune response, Rho(D) immune globulin (e.g., RhoGAM) is administered, which binds with Rh-positive fetal red blood cells that may enter the maternal circulation, obstructing the sensitization process.
Without RhoGAM, the maternal immune system might attack the red blood cells in any subsequent Rh-positive fetuses, causing serious complications such as anemia, brain damage, or even death. Fortunately, with proper prenatal care and the administration of RhoGAM during and after pregnancy, the risk of HDN is greatly reduced. The treatment for HDN may involve pre-birth transfusions and exchange transfusions after birth to manage the condition and prevent complications.