How does anti-D immunoglobulin help in preventing Rhesus disease?

Anti-D immunoglobulin plays a crucial role in preventing Rhesus disease, also known as hemolytic disease of the newborn (HDN), by specifically addressing the issue of Rh incompatibility between an Rh-negative mother and her Rh-positive fetus. When an Rh-positive fetus is carried by an Rh-negative mother, there's a risk that the mother's immune system will recognize the Rh-positive red blood cells (RBCs) as foreign and produce antibodies against them. This immune response can lead to the destruction of the fetal RBCs, resulting in Rhesus disease.

Administering anti-D immunoglobulin to the mother effectively prevents this immune response. The anti-D immunoglobulin binds to any Rh-positive fetal red blood cells that may enter the maternal circulation, effectively masking them and preventing the mother's immune system from recognizing them as foreign. This action helps to avoid the production of maternal antibodies against the Rh-positive blood cells, thereby preventing the complications associated with Rhesus disease.

In light of this, the option that correctly describes how anti-D immunoglobulin functions in this context is that it helps by preventing the maternal immune response that leads to the destruction of fetal red blood cells.