Early viscoelastometric guided fibrinogen replacement combined with escalation of clinical care reduces progression in postpartum haemorrhage: a comparison of outcomes from two prospective observational studies

•Viscoelastometric haemostatic assays allow targeted correction of fibrinogen ≤2 g/L.•Correction of fibrinogen ≤2 g/L with escalated care reduced PPH progression.•Reduced progression was greatest in women with fibrinogen ≤2 g/L at first testing.•These data support fibrinogen ≤2 g/L as a therapeutic target in obstetric bleeding. Viscoelastometric haemostatic assays (VHA) give rapid information on coagulation status, allowing individualised resuscitation. This paper compares outcomes from two observational studies of postpartum haemorrhage (PPH) in the same institution, before and after practice changed from fixed ratio empirical transfusion of coagulation products with laboratory coagulation testing to VHA-guided fibrinogen replacement incorporated into an enhanced PPH care bundle. In both studies, all blood samples were taken near 1000 mL qualitative blood loss (QBL). In Study One, QBL started once PPH was identified, and resuscitation with coagulation blood products was empirical or based on laboratory tests of coagulation. In Study Two, QBL started at delivery and VHA was used to guide fibrinogen replacement if FIBTEM A5 was 12 mm. Improved PPH outcomes were observed in Study Two, with rates of measured blood loss ≥2500 mL, ≥4 units red blood cell (RBC) transfusion, fresh frozen plasma transfusion and ≥8 units of any blood product transfusion all reduced (P