The impact of population migration on the distribution of blood groups in Poland

Introduction: The distribution of blood groups in a population plays a crucial role in the organisation of transfusion services, blood donation strategies, and the planning of healthcare resources. Despite its importance, Poland has not conducted a nationwide analysis of blood group prevalence since 1959. Aim: To evaluate the distribution and temporal changes of ABO and RhD blood groups among blood donors in Poland over the past decade, and to assess their compatibility with blood group profiles of patients treated at a haematology centre. Material and methods: This retrospective study analysed anonymised data from three sources: (1) the National Register of Blood Donors (NBDR), containing 5.4 million records from 2013 to 2023; (2) the hospital and laboratory information systems of the Institute of Hematology and Transfusion Medicine (IHTM), covering 26,781 patients from 2013 to 2023; and (3) demographic data from the Local Data Bank of Statistics Poland (GUS), used to assess population migration. Blood group distributions were analysed by year, gender, age, and voivodeship. Results: Among 2.16 million unique donors from the NBDR dataset, the following distribution was observed: blood group O — 34.35%, A — 37.72%, B — 19.69%, AB — 8.24%. RhD-positive individuals accounted for approximately 84% of donors. The distribution was consistent across most regions and remained stable over time. Similar proportions were found among patients treated at the IHTM. Minor regional differences were identified, potentially related to migration patterns. Conclusions: The distribution of ABO and RhD blood groups in Poland has remained stable over the last decade. The findings from this nationwide study may support effective planning and optimisation of blood supply systems. Knowledge of blood group prevalence is essential for managing rare blood types and adapting to demographic shifts.