Trends and determinants of peripartum blood transfusions

BACKGROUND: Blood transfusion is critical in mitigating blood loss during delivery, but the epidemiology of peripartum blood transfusion in the United States is not fully understood. The objective of this study was to estimate trends in peripartum blood transfusions, including severe hemorrhage, and identify transfusion risk factors. STUDY DESIGN AND METHODS: A retrospective cohort was assembled from the Recipient Epidemiology and Donor Study IV Pediatric (REDS-IV-P) database, which includes a network of hospitals and blood centers across four U.S. regional hubs. This included in-hospital deliveries ≥24 weeks gestation from 2019 to 2024, with the outcome being any peripartum (within ±7 days of delivery) blood product transfusion. Bayesian Model Averaging (BMA) was used to examine associations. RESULTS: There were 158,322 deliveries, with transfusion occurring in 4246 (11% were severe hemorrhage). Overall incidence of transfusion increased from ~2% early in the study period to ~3% in later years (p < 0.001). The odds of peripartum transfusion were higher for deliveries where patients had an underlying hemoglobinopathy (adjusted odds ratio [aOR] [95% confidence interval; CI] aOR = 3.35 [2.65, 4.24]), venous thromboembolism (aOR = 3.25 [2.47, 4.26]), received hemostatic factor (aOR = 10.30 [9.58, 11.06]), mechanical ventilation (aOR = 13.91 [8.76, 22.11]), or hysterectomy (aOR = 13.68 [9.86, 18.96]). CONCLUSION: Peripartum transfusions are increasing across the REDS-IV-P hubs and are associated with underlying medical-obstetric risk factors such as bleeding disorders and hemoglobinopathies. Our findings support the importance of early prenatal healthcare and identification of conditions that may help prevent peripartum hemorrhage and associated transfusions.