Predelivery maternal fibrinogen as a predictor of blood loss after vaginal delivery.

In this prospective single-centre cohort study, Niepraschk-von Dollen et al. found that predelivery fibrinogen level was significantly associated with the risk of severe postpartum haemorhage (PPH), defined as blood loss >1000 mL, after a vaginal delivery. For each decrease of 1 g/L of the predelivery fibrinogen level, the risk of severe PPH increases by a factor of 2.5.

This prospective observational study was performed in a tertiary hospital in Berlin and included 809 parturients who had a vaginal delivery at term after a singleton pregnancy. Missing data were observed in 120 women (15%).

It has already been well demonstrated that low fibrinogen level (<2 g/L) measured in women with PPH is the best predictor for severe PPH (Charbit et al. J Thromb Haemost 2007; Cortet et al. Br J Anaesth 2012). In the present study, the objective was to explore the association between fibrinogen level measured before the occurrence of PPH and the risk of PPH and/or severe PPH.

Fibrinogen levels were measured predelivery in order to identify predictive factors that may be used before delivery. The second difference with preexisting studies is that blood loss was measured with a collector bag and collected prospectively, providing a more accurate estimation of blood loss than clinician’s assessment.

However, the authors found that sensitivity and specificity of predelivery fibrinogen level to predict severe PPH are very low. This can be easily explained by the fact that coagulopathy is a complication of PPH and appears mostly in parturients with normal predelivery fibrinogen levels. Consequently, the clinical implications of this study are limited and do not lead to changes in PPH management.

– Marie-Pierre Bonnet