Final answer:
A woman with Rh-negative blood receives Rh immunoglobulin (RhoGAM) within 72 hours of giving birth to prevent Hemolytic Disease of the Newborn (HDN) in future pregnancies by stopping the formation of antibodies against Rh-positive fetal blood cells.
Step-by-step explanation:
Within 72 hours of giving birth, a woman with Rh-negative blood receives Rh immunoglobulin. This medication, commonly known as RhoGAM, is very effective in preventing Hemolytic Disease of the Newborn (HDN). If an Rh-negative woman carries an Rh-positive baby, she can form antibodies against the baby's Rh-positive red blood cells. These antibodies could harm a future Rh-positive baby by destroying its red blood cells. To prevent this, Rh immunoglobulin is administered, which contains antibodies that target and destroy any Rh-positive fetal red blood cells that have entered the mother's circulation, thus preventing the mother's immune system from reacting against them.
RhoGAM is crucial for preventing the mother's immune system from becoming sensitized to Rh-positive blood cells, which could cause issues in subsequent pregnancies. The introduction of RhoGAM has significantly reduced the incidence of HDN from about 13-14% to 0.1% in the United States since 1968.