Abstract
BACKGROUND/AIM: This study aimed to comprehensively analyze the distribution of ABO and Rh blood groups, as well as demographic characteristics and regional variations, using data from 9.5 million blood donors across Türkiye. MATERIALS AND METHODS: In this multicenter, retrospective, cross-sectional study, data were collected from 9,587,592 healthy, voluntary donors who donated to the Turkish Red Crescent between 1998 and 2021. Donors met the criteria of being 18-70 years old, weighing over 50 kg, with hemoglobin levels above 13.5 g/dL for males and 12.5 g/dL for females. The data were evaluated based on age, sex, education level, and geographic region. RESULTS: The ABO blood group distribution was determined as follows: A (42.1%), O (34.0%), B (16.4%), and AB (7.5%). When analyzed together with the Rh factor, A Rh (+) was the most common (37.1%), while AB Rh (-) was the least common (0.9%). Regional analyses showed that A Rh (+) was highest in the Black Sea Region, whereas the Aegean Region had a notably high AB Rh (+) rate. The Marmara Region had the highest total number of donors, while Eastern Anatolia had the highest donation rate relative to its population. Demographically, 82.0% of donors were male; the 18-34 age group represented the most active segment (50.5%), and high school graduates had the highest donation rate (31.2%). CONCLUSION: This study provides a detailed profile of Türkiye's blood donors, filling a gap in national blood group data. The findings support optimizing transfusion services, improving blood supply management, and refining donor recruitment strategies. Regional and demographic disparities highlight the need for targeted awareness campaigns. Addressing sex imbalances and increasing participation from underrepresented groups can enhance sustainability. Additionally, these findings contribute valuable data for clinical applications, epidemiological studies, and future healthcare policy development.