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

Article type: Research Article

Authors: Ahmadzia, H.K.^{a; *} | Lockhart, E.L.^b | Thomas, S.M.^c | Welsby, I.J.^d | Hoffman, M.R.^e | James, A.H.^a | Murtha, A.P.^a | Swamy, G.K.^a | Grotegut, C.A.^a

Affiliations: [a] Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Duke University, Durham, NC, USA | [b] Department of Pathology, Division of Pathology Clinical Services, Duke University, Durham, NC, USA | [c] Department of Biostatistics, Duke University, Durham, NC, USA | [d] Department of Anesthesiology, Division of Cardiac Anesthesiology, Duke University, Durham, NC, USA | [e] Department of Pathology, Division of General Pathology, Duke University Durham, NC, USA

Correspondence: [*] Address for correspondence: Homa K. Ahmadzia, MD, MPH, Department of Obstetrics and Gynecology, The GeorgeWashington University, 2150 Pennsylvania Ave, NW, Washington DC 20037, USA. Tel.: +1 202 741 2500; Fax: +1 202 741 2550; E-mail: [email protected].

Abstract: 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 ɛ-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 ɛ-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. 57.5 mm, 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, 66.3 mm, respectively; p = 0.25) or mean CT (409, 412, 420, 424 sec; p = 0.30) after addition of tranexamic acid. Similar results were found using ɛ-aminocaproic acid. Preeclamptic women had a higher mean MCF after the addition of ɛ-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.

Keywords: Antifibrinolytic therapy, maximum clot firmness, postpartum haemorrhage, thromboelastometry, tranexamic acid

DOI: 10.3233/NPM-16139

Journal: Journal of Neonatal-Perinatal Medicine, vol. 10, no. 1, pp. 1-7, 2017