Single vs. Two-Unit Transfusion for Hemodynamically Stable Postpartum Anemia: Less is More

Objective: Postpartum anemia (PPA) occasionally may necessitate transfusion of packed red blood cells (pRBCs). There has been debate among obstetricians regarding administering a single unit as opposed to two-unit protocol. A recent trial showed that using the single unit protocol avoided transfusion of the second unit in 80% of patients. However, risk factors for identifying patients who would benefit from two units of pRBCs had not been evaluated. Methods: Retrospective cohort study during 2010–2020. The study group included women with PPA who received transfusion of pRBCs. The groups were divided into patients who received single versus two units of pRBCs. The primary outcome was to identify risk factors that demand a two-unit protocol.Results: The final analysis included 368 women who received single unit compared with 317 women receiving two units pRBCs. In univariate analysis, the duration of cesarean delivery (56.6 ± 35.8 vs. 45.5 ± 18.5 min, p=0.0063), episiotomy during vaginal delivery, lowest postpartum mean Hb levels (6.6 ± 0.6 g/dl vs. 6.9 ± 0.5 g/dl, p=0.0001) and mean delta of Hb levels (4.3 ± 1.5 g/dl vs. 3.9± 1.5 g/dl, p=0.002) were significant risk factors for requiring two pRBCs compared to a single unit. Despite our findings, in a multivariate analysis, none of the risk factors was significantly associated with the two-pRBCs protocol. Conclusions: Our study supports the practice of single unit protocol in patients with PPA regardless of the risk factors present. Following these guidelines will help obstetricians reduce costs and morbidity associated with pRBCs transfusion.