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Antithrombotics in the Prevention of Recurrent Pregnancy Loss, The Use of (Scientific Impact Paper No. 26)

Published: 24/06/2011

This is the first edition of this Scientific Impact Paper.


Update July 2015: New evidence and guidance in this field were reviewed in 2014 and it was decided that revision of this guideline would be deferred to a later date. The version available on the website will remain valid until replaced.


Over the last 5 years, there has been a large increase in the use of aspirin and low-molecular-weight heparin (LMWH) to attempt to prevent pregnancy loss. Until recently, robust clinical evidence to examine this practice was lacking.

In 2009, a Cochrane review of anticoagulants for nonantiphospholipid recurrent pregnancy loss indentified only two studies of 189 women. Neither study showed a benefit of one treatment over another. The Cochrane review concluded that there was no evidence for this practice and identified the urgent need for further trials. Furthermore, even in the case of antiphospholipid syndrome (APS)-associated pregnancy loss, no benefit was found in an analysis of three trials of aspirin compared with placebo.

The purpose of this opinion paper is to discuss the rationale behind the use of antithrombotics in women with recurrent pregnancy loss.