Final answer:
Hemolytic disease of the newborn (HDN) occurs when a mother who is Rh- carries an Rh+ fetus. Maternal anti-Rh antibodies attack and destroy fetal Rh+ red blood cells, causing hemolysis. HDN can be prevented with the administration of Rho(D) immune globulin.
Step-by-step explanation:
Hemolytic disease of the newborn (HDN), also known as erythroblastosis fetalis, occurs when a mother who is Rh- carries an Rh+ fetus. This happens when maternal anti-Rh antibodies cross the placenta and attack and destroy fetal Rh+ red blood cells, leading to hemolysis.
During the first pregnancy, if fetal blood enters the mother's circulatory system, anti-Rh antibodies are produced in response. These antibodies can then cross the placenta during subsequent pregnancies and target the Rh+ red blood cells of the fetus, causing hemolysis.
Fortunately, HDN can be prevented through the administration of Rho(D) immune globulin, which prevents the formation of anti-Rh antibodies in the mother. This medication is given during the first pregnancy with an Rh+ fetus, ensuring minimal risk of HDN in subsequent pregnancies.