Background: ABO and Rh blood grouping discrepancies are significant causes of transfusion-related morbidity and mortality. Most of these errors occur when blood grouping standards are unavailable or misinterpreted. This study determined the rate of such errors among hospitals in Zahedan, a city in southeast Iran. We also assessed the prevalence of ABO and Rh grouping errors in the Iranian Blood Transfusion Organization (IBTO) in Zahedan.
Method: During the study, 30,254 blood bags were sent to five of Zahedan's hospitals. Pre-transfusion ABO and Rh blood grouping was carried out by slide method. Any sample showing a discrepancy between IBTO and hospital laboratory was returned to IBTO for identification of the error by the American Association of Blood Banking (AABB) standards protocol.
Results: We observed 420 discrepancies in the pre-transfusion ABO and Rh blood grouping of 30,254 units, a 1.4 percent error, among Zahedan hospitals. The most common error was misidentification of group A as O (62 cases), while group B was misidentified as O in 41 cases. We discovered critical errors, such as misdiagnosis of A as B and vice versa, which could endanger the patient’s life. We also noted 20 misidentifications in routine IBTO laboratory testing, a 0.02 percent error.
Conclusion: The high incidence of pre-transfusion blood grouping errors emphasizes the necessity of always using standard forward and reverse grouping tests in hospitals.