Using antifibrinolytics in the peripartum period-concern for a hypercoagulable effect?

Document Type

Journal Article

Publication Date



Journal of Neonatal-Perinatal Medicine








Antifibrinolytic therapy; maximum clot firmness; postpartum haemorrhage; thromboelastometry; tranexamic acid


© 2017-IOS Press and the authors. INTRODUCTION: Although antifibrinolytic agents are used to prevent and treat hemorrhage, there are concerns about a potential increased risk for peripartum venous thromboembolism. We sought to determine the impact of tranexamic acid and ϵ-aminocaproic acid on in vitro clotting properties in pregnancy. METHODS: Blood samples were obtained from healthy pregnant, obese, and preeclamptic pregnant women (n=10 in each group) prior to delivery as well as from healthy non-pregnant controls (n=10). Maximum clot firmness (MCF) and clotting time (CT) were measured using rotation thromboelastometry in the presence of tranexamic acid (3, 30, or 300 μg/mL) or ϵ-aminocaproic acid (30, 300, or 3000 μg/mL). ANOVA and regression analyses were performed. RESULTS: Mean whole blood MCF was significantly higher in healthy pregnant vs. non-pregnant women (66.5 vs. 57.5mm, p<0.001). Among healthy pregnant women, there was no significant difference between mean MCF (whole blood alone, and with increasing tranexamic acid doses=66.5, 66.1, 66.4, 66.3mm, respectively; p=0.25) or mean CT (409, 412, 420, 424sec; p=0.30) after addition of tranexamic acid. Similar results were found using ϵ-aminocaproic acid. Preeclamptic women had a higher mean MCF after the addition of ϵ-aminocaproic acid and tranexamic acid (p=0.05 and p=0.04, respectively) compared to whole blood alone. CONCLUSIONS: Pregnancy is a hypercoagulable state, as reflected by an increased MCF compared to non-pregnant women. Addition of antifibrinolytic therapy in vitro does not appear to increase MCF or CT for non-pregnant, pregnant, and obese women. Whether antifibrinolytics are safe in preeclampsia may require further study.