Final answer:
Anti-D Ig (RhoGAM) should be administered to Rh-negative women during weeks 26-28 of pregnancy and within 72 hours after delivery to prevent hemolytic disease of the newborn (HDN) in cases of Rh incompatibility.
Step-by-step explanation:
The standard dose of anti-D Ig, also known as RhoGAM, should be administered during pregnancy typically between weeks 26-28 and within 72 hours following birth. RhoGAM plays a crucial role in preventing hemolytic disease of the newborn (HDN) by destroying any fetal Rh-positive erythrocytes that may cross the placental barrier, thus preventing the mother's immune system from producing antibodies against them. It is especially important for Rh-negative mothers who are pregnant with an Rh-positive fetus. The use of RhoGAM during and after pregnancy has significantly reduced the incidence of HDN from about 13-14 percent to 0.1 percent in the United States since its introduction in 1968. Additionally, in cases where there might be a risk of transplacental hemorrhage, due to procedures like amniocentesis, additional doses may be necessary.