Evaluation of blood type as a potential risk factor for hemorrhage during vaginal hysterectomy

Objective: To examine the association between the O blood type and bleeding tendency in patient undergoing vaginal hysterectomy.Methods: This was a retrospective cohort study including all women who had undergone vaginal hysterectomy at our institution between January 2015 and September 2020. All women underwent blood type and complete blood count testing pre- and post-operatively. The estimated intraoperative blood loss, the need for blood transfusion, pre- and postoperative hemoglobin and hematocrit measurements and surgical data were recorded for all patients. Patients with known coagulopathies or those taking antithrombotic medications were excluded from the study. Statistical analysis was performed using student t, chi 2, Fischer exact, and ANOVA tests as well as a stepwise logistic regression model.Results: The study included 106 patients (35.2 %) with O and 195 patients (64.8 %) with non-O (i.e., A, B or AB) blood types. The O blood type was significantly associated with a higher risk for moderate blood loss (defined as a pre- to postoperative Hb or HCT drop >2gr or >6 %, respectively) (p = 0.012), but not with severe (defined as a Hb or HCT drop of >3gr or >9 %, respectively) perioperative bleeding, nor with the need for blood transfusion.Conclusion: The O blood type was found to be significantly associated with moderate but not with severe intraoperative bleeding during and following vaginal hysterectomy.