HPE CSL Managing Perioperative Bleeding handbook - Page 15

Pregnancy and post-partum Fibrinogen and post-partum haemorrhage Because hypofibrinogenemia is a major and early part of post-partum haemorrhage-associated coagulopathy, fibrinogen supplementation appears to be one of the most promising targets for this haemostatic intervention Anne-Sophie Ducloy-Bouthors Anne-Sophie Baptiste Pole anesthésie-réanimation, maternité Jeanne de Flandre, academic hospital, avenue Oscar Lambret, Lille, France Cyril Huissoud Pole Obstétrique et Gynécologie Hôpital Croix Rousse Hospices Civils 103 Grande Rue de la Croix-Rousse, Lyon, France Post-partum haemorrhage (PPH) is the leading cause of maternal mortality and morbidity in Europe and worldwide. 1,2 PPH following vaginal delivery is due to uterine atony, retained placental products and placental abnormal implantation, genital-tract trauma and systemic medical disorders. A large proportion of women who develop PPH do not have previous identifiable risk factors; so all women must be considered at risk. Antenatal screening is important to detect high risk parturients using the 4T rule: Tone, Tissue, Trauma, and Thrombin. 3 Acquired coagulopathy (hypofibrinogenemia and hyperfibrinolysis) appears early in the course of PPH, worsening its prognosis by increasing the bleeding volume. 4,5 The diagnosis and treatment of the acquired coagulopathy is a part of the PPH management protocol in parallel with uterotonics, obstetrical procedures and transfusion. 3 Hypofibrinogenemia is a risk marker of PPH severity Fibrinogen is a central substrate for clot formation. It is the main thrombin substrate leading, through fibrin monomers and their polymerisation, to fibrin clot formation. Fibrinogen is also the target of plasmin in excess. Fibrinogenolysis has been identified as a major component in PPH, trauma, and massive haemorrhage-induced coagulopathy. 6–8 Charbit et al demonstrated, in 128 women with PPH requiring prostaglandin administration, that plasma fibrinogen concentration at enrolment was the sole independent predictive factor for poor outcome. 4 A plasma fibrinogen level under a 2g/l threshold showed a predictive value for progression toward severe bleeding of 100% (CI 95% 79–100). This level was higher than the ‘historical’ threshold of <1g/l, which indicated in the general population the need to initiate replacement therapy, or the 1.5g/dl threshold identified by Grottke et al in an experimental animal setting. 9 This higher threshold could be explained by a higher than normal plasma fibrinogen level during pregnancy and the post-partum period. 10 An analysis by Cortet et al of 738 women with PPH clearly confirmed the importance of fibrinogen levels. 11 The mean plasma fibrinogen concentration at diagnosis was 4.2g/l (SD= 1.2g/l) among 15 hospitalpharmacyeurope.com