The study investigated the effect of transfusions matched for five Rh antigens (D, C, c, E, e) on patients requiring repeated red blood cell transfusions. Patients with five Rh antigen-matched transfusions were found to have a significantly lower incidence of alloantibody formation and fewer transfusion-related adverse reactions. This group also showed reduced red blood cell utilization, longer intervals between transfusions, and shorter hospital stays. Transfusion matched for five Rh antigens was independently associated with lower RBC utilization even after adjustment for clinical variables. The study suggests that this strategy may be beneficial for patients at high risk of alloimmunization. Further multicenter studies are needed to assess the long-term clinical value and cost-effectiveness of this approach.