Related Experiment Video
Updated: May 22, 2025
Experimental and Imaging Techniques for Examining Fibrin Clot Structures in Normal and Diseased States
Published on: April 1, 2015
The CPLAN study: Clotting Parameters after medicaL AbortioN
John J Reynolds-Wright1,2, Alastair F Nimmo3, Julia A M Anderson4
1Centre for Reproductive Health, University of Edinburgh, Edinburgh, United Kingdom.
Background:
There is paucity of information on coagulation parameters throughout pregnancy, the puerperium, and post-abortion - and how these relate to venous thromboembolism (VTE) risk. Guidance for thromboprophylaxis post-abortion is guided by expert opinion and extrapolated from post-birth, with recommendations varying from 0 to 6 weeks duration.
Methods:
We conducted a study in a community abortion clinic in Edinburgh, UK March-August 2021. We recruited healthy pregnant women requesting medical abortion (<12 weeks gestation) and healthy, non-pregnant women (controls). Blood samples were taken prior to abortion and 10-14 days afterwards. Controls provided a single sample. We assessed laboratory markers of coagulation (Clauss-fibrinogen, prothrombin time, activated partial thromboplastin time, platelets) and viscoelastic measures using the ClotPro® system. We compared the control group with the pregnancy group pre- and post-abortion.
Results:
We recruited 45 women (24 pregnant, 21 non-pregnant). Clauss-fibrinogen was significantly elevated pre-abortion compared to controls (3.4 g/L vs 2.8 g/L, p = 0.04), although remained within normal range. Two viscoelastic measures showed pro-coagulant changes, one pre-abortion and one post-abortion compared to controls. The absolute differences were small and remained within normal ranges.
Conclusion:
There were minimal differences in measures of coagulation in first trimester pregnancy, that largely resolved 10-14 days after medical abortion. Shorter courses of thromboprophylaxis might be sufficient compared to post-birth for those at high risk of VTE.
