Final answer:
The RhoGAM shot is given to Rh-negative pregnant individuals during weeks 26-28 of pregnancy and within 72 hours after birth, to prevent the development of Rh antibodies that might endanger the fetus in current and future pregnancies.
Step-by-step explanation:
The RhoGAM shot is crucial in preventing hemolytic disease of the newborn (HDN) in cases of Rh incompatibility between an Rh-negative parent and Rh-positive fetus. This drug, also known as Rh immune globulin, is typically administered during weeks 26-28 of pregnancy and again within 72 hours following birth. It operates by destroying any fetal Rh-positive erythrocytes that may cross the placental barrier, thereby preventing the mother's immune system from developing antibodies that could endanger future pregnancies. RhoGAM has drastically reduced the incidence of HDN since its introduction in 1968 from roughly 13-14 percent to about 0.1 percent in cases without preventive treatment.