Normal pregnancy is associated with an increase in thrombin generation from the very early stages of the first trimester

Bagot, C.N., Leishman, E., Onyiaodike, C.C., Jordan, F. and Freeman, D.J. (2017) Normal pregnancy is associated with an increase in thrombin generation from the very early stages of the first trimester. Thrombosis Research, 157, pp. 49-54. (doi: 10.1016/j.thromres.2017.06.027) (PMID:28692840)

Abstract

Background: Pregnancy is a hypercoagulable state associated with an increased risk of venous thrombosis, which begins during the first trimester, but the exact time of onset is unknown. Thrombin generation, a laboratory marker of thrombosis risk, increases during normal pregnancy but it is unclear exactly how early this increase occurs. Methods: We assessed thrombin generation by Calibrated Automated Thrombography in women undergoing natural cycle in vitro fertilization, who subsequently gave birth at term following a normal pregnancy (n = 22). Blood samples were taken just prior to conception and repeated five times during very early pregnancy, up to Day 59 estimated gestation. Results: Mean Endogenous Thrombin Potential (ETP), peak thrombin generation and Velocity Index (VI) increased significantly from pre-pregnancy to Day 43 gestation (p = 0.024–0.0004). This change persisted to Day 59 gestation. The mean of the percentage change from baseline, accounting for inter-individual variation, in ETP, peak thrombin and VI increased significantly from pre-pregnancy to Day 32 gestation (p = 0.0351–<0.0001) with the mean increase from baseline persisting to Day 59 gestation. Conclusion: Thrombin generation increases significantly during the very early stages of normal pregnancy when compared to the pre-pregnancy state. The increased risk of venous thrombosis therefore likely begins very early in a woman's pregnancy, suggesting that women considered clinically to be at high thrombotic risk should start thromboprophylaxis as early as possible after a positive pregnancy test.

• Item Type: Articles
• Additional Information: The study was funded by the charity, Wellbeing of Women (Wellbeing of Women/RCOG Research Grant; RG939/07).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Freeman, Dr Dilys and Jordan, Mrs Fiona and Bagot, Dr Catherine
• Authors: Bagot, C.N., Leishman, E., Onyiaodike, C.C., Jordan, F., and Freeman, D.J.
• College/School: College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health; College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Journal Name: Thrombosis Research
• Publisher: Elsevier
• ISSN: 0049-3848
• ISSN (Online): 1879-2472
• Published Online: 29 June 2017
• Copyright Holders: Copyright © 2017 Elsevier Ltd.
• First Published: First published in Thrombosis Research 157: 49-54
• Publisher Policy: Reproduced in accordance with the publisher copyright policy