Clinical and biological factors associated with red blood cell transfusion during severe postpartum haemorrhage - A single-center retrospective cohort study.

Introduction: Red blood cell (RBC) transfusions are of utmost importance in the management of severe post-partum haemorrhage. Although the recommendations for blood transfusion protocols are regularly issued, there are significant differences in management depending on the context and the medical teams involved.

Objective: To determine during the first 24 h, the clinical and biological factors associated with the decision for RBC transfusion during severe PPH (≥1000 mL) for vaginal and caesarean deliveries.

Study Design: Monocentric retrospective study conducted in a tertiary care university maternity unit (CHI-Creteil) including all parturients from November 23th 2018 to 31th December 2020 with severe PPH (≥1000 mL).

Results: Over the study period, we reported 7103 deliveries, out of which 682 were complicated by PPH (9.6 %) with 200 cases of PPH ≥1000 mL (2.8 %). In our study, 40 % of patients (80/200) required a RBC transfusion". After multivariate analysis, severe PPH caused by placental abruption, uterine rupture or placental implantation disorders (aOR = 3.48 IC95 [1.27-9.52], p < 0.001), estimated blood loss ≥1500 mL (aOR = 9.60 IC95 [3.69-24.95], p < 0. 001), invasive measures such as uterine balloon tamponade, arterial ligation and uterine packing (aOR = 4.15 IC95 [1.80-9.61], p < 0.001), pre-labor hemoglobin <10 g/dL (aOR =4.88 IC95 [1.57-15.15], p < 0.001) or abnormal biological results in the acute phase (including hemoglobin <7.0 g/dL and/or fibrinogen <2 g/L and/or platelets <100 G/L) (aOR =356 IC95 [1,05-12,10], p < 0.001) were significantly and independently associated with the decision to initiate RBC transfusions.

Conclusions: In a monocentric retrospective study including 200 consecutive cases of severe PPH (≥1000 mL) we identified groups of clinical and biological factors directly accessible to clinicians, significantly and independently associated with RBC transfusion in the first 24 h of management.