Changes in Blood Groups of Patients Cared for in a Third Level Hospital in Istanbul Over the Years.

Background: There has been a large number of immigration to Turkey after 2011, and in the past 13 years, a mixed population has been formed with both the transition to Turkish citizenship and high fertility rates. Along with numerous human migrations, gene trait transfer also occurs. This study aimed to investigate the effects of migration on blood group changes in Turkey by determining the blood group distribution of Turkish citizens living in Turkey, the blood group distribution of foreign nationals coming to Turkey, and the blood group distribution of 0-year-old babies born in the last four years.

Methods: Patients whose blood types were checked at our hospital between 2020 and 2024 were included in the study. For each patient, age, gender, citizenship identification numbers, ABO, and Rh blood groups were obtained from medical records. These constituted the study data.

Results: Blood group tests were requested for 507,959 patients in our hospital. A total of 49.8% of them were female and 50.2% were male. The mean age was 38.2 ± 19.1 years. Citizens of the Republic of Turkey constituted 92.7% of the blood groups examined, and of these, A, B, AB, and O blood groups were found to be 44.2%, 15.2%, 7.1%, and 33.6%, respectively. Out of the Rh blood groups, 87.5% were Rh positive and 12.3% were Rh negative. Foreign Turkish citizens constituted 6.5% of the examined blood groups, and A, B, AB, and O blood groups were found to be 36.7%, 20.4%, 8.0%, and 34.9%, respectively; 90.2% of Rh blood groups were Rh positive and 9.7% were Rh negative. When the blood groups of babies born between 2020 - 2024 were examined, ABO and Rh blood groups were similar to the general blood group distribution of Turkey, and there was no difference. In addition, among all blood groups, the A2 and A2B rates were found to be 0.01% and 0.005%, and the variant (weak D - Partial D) Rh blood group rate was 0.2%.

Conclusions: In this study, the blood groups of foreign nationals who migrated to Turkey and became citizens were found to be statistically, significantly different from the Turkish blood group distribution (p < 0.05). The blood group distribution of babies born in the last four years still reflected the same blood group distribution as the Turkish blood group distribution. Good blood stock management is required to avoid problems in blood supply. In Turkey, which has become a mixed population due to migration, it was thought that these results could be a guide in the supply of blood and blood products needed by patients and that they would also contribute to our country's blood group database and world literature.