Final answer:
RhoGAM treatment at 28 weeks aims to keep the mother's anti-D titer low and prevent hemolytic disease of the newborn (HDN) by destroying Rh-positive fetal erythrocytes that cross into the maternal circulation.
Step-by-step explanation:
The administration of Rh immunoglobulin (RhIG), commonly known as RhoGAM, during the 28th week of pregnancy is a preventative treatment used to protect an Rh-negative mother from becoming sensitized to Rh-positive red blood cells, which could potentially pose a serious threat to an Rh-positive fetus. RhoGAM acts by destroying any Rh-positive fetal erythrocytes that enter the mother's bloodstream, thus preventing her immune system from producing anti-D antibodies. Therefore, the RhIG treatment at 28 weeks is intended to keep the mother's anti-D titer low and avert the harmful effects of hemolytic disease of the newborn (HDN).