Rare Donors Case Study: A pregnancy with Anti-U, a challenge in countries with developing rare donor programs

This case study was prepared by Paula Andrea Gaviria García and Sara Lucia Ramirez Tapias from Bogotá D.C, Colombia. They are members of the ISBT Rare Donors Working Party. The study describes the management of a pregnant patient with a rare red cell phenotype and a clinically significant antibody against a high-prevalence antigen. The clinical situation was urgent due to suspected haemolytic disease of the fetus and newborn, while compatible blood was extremely difficult to source within a developing rare donor programme. The case highlights challenges in donor availability, population diversity, interdisciplinary coordination, and the need to strengthen rare donor registries and targeted recruitment strategies.