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Thrombosis and Embolism during Pregnancy and the Puerperium, Reducing the Risk (Green-top Guideline No. 37a)

Published: 18/11/2009

Update November 2014: This guideline is currently being revised, with publication anticipated early 2015. The version available on the website and app will remain valid until replaced.

This is the second edition of this guideline, which was published in 2004 under the title Thromboprophylaxis during Pregnancy, Labour and after Vaginal Delivery. Please note: this guideline was previously Green-top Guideline No. 37.

This guideline reviews the risk factors for venous thromboembolism (VTE) in pregnancy and the puerperium and provides guidance as to which women require thromboprophylaxis in and after pregnancy. It reviews the safety and efficacy of different forms of thromboprophylaxis. For the diagnosis and management of acute VTE in pregnancy, please refer to Green-top Guideline No. 37b: The Acute Management of Thrombosis and Embolism during Pregnancy and the Puerperium.

This guideline covers thromboprophylaxis after caesarean section and thus it replaces the previously published Report of the RCOG Working Party on Prophylaxis Against Thromboembolism in Gynaecology and Obstetrics from 1995. This guideline excludes the management of pregnancy loss and other pregnancy complications, even in women with documented thrombophilia.

A summary of the guideline for antenatal and postnatal thromboprophylaxis is given in Figure 1 and the 23 recommendations are listed in the executive summary at the start of the guideline. As is apparent from the low grading of the evidence for many of the recommendations, they have been developed to provide a broad practical guide for obstetricians in clinical practice. However, it is recognised that, in individual women, alternative approaches may be reasonable, particularly following discussion with the woman concerned and, where available, input from a local expert in the field of thrombosis in pregnancy.

Of note, the National Institute for Health and Care Excellence (NICE) guideline on venous thromboembolism includes pregnancy and the puerperium as risk factors. This RCOG guideline aims to be consistent with the clinical practice recommendations included in the NICE guideline.