Prevalence of Rhesus D negativity among reproductive age women in Southern Ethiopia: a cross-sectional study.

Background: The Rhesus (Rh) blood group system is the next most clinically significant blood group system following the ABO blood group. Rh D-negative women are at risk of alloimmunization following exposure to Rh D-positive blood. The exposure of Rh D-negative women to Rh D-positive fetal blood may cause hemolytic disease of the fetus or new-born due to Rh incompatibility.