Medical Laboratory Scientist ASCP Practice Exam 2025 – Complete Study Guide

The incidence of hemolytic disease of the fetus and newborn (HDFN) due to anti-D antibodies is influenced by the prevalence of Rh factor incompatibility in the population. In general, the anti-D immunoglobulin plays a critical role in preventing sensitization of Rh-negative mothers to the Rh-positive blood of their fetuses, which can result in HDFN.

Asians, particularly Central and Southeast Asians, have a higher prevalence of Rh-positive blood groups compared to other populations such as Caucasians, Africans, and Hispanics. This greater prevalence of Rh-positive individuals leads to a lower incidence of Rh incompatibility between Rh-negative mothers and Rh-positive fetuses. Consequently, the occurrence of hemolytic disease arising from anti-D antibodies is rare in this group.

Caucasians have a significant proportion of Rh-negative individuals, making them more susceptible to Rh incompatibility and, therefore, a higher incidence of anti-D associated HDFN. Hispanics and Africans also exhibit varying prevalence rates of Rh-negativity, but these rates still do not approach the rarity observed in Asians. Hence, the population group with the least incidence of hemolytic disease due to anti-D is indeed the Asian population.