Position statement – September 2026
The Royal College of Obstetricians and Gynaecologists (RCOG) is currently updating Green-top Guideline (GTG) No. 37a Reducing the Risk of Venous Thromboembolism during Pregnancy and the Puerperium. This update is being led by the 37a guideline developer team.
Pending publication of the updated guideline, clinicians should follow the current GTG No. 37a, but with the amendments as set out below, which align with the NHS England Maternal Care Bundle (MCB). Clinicians should also follow the MCB recommendations relating to women in the first trimester of pregnancy and those who experience miscarriage or choose to end their pregnancy.
While the update is in progress, it is suggested clinicians in Wales, Scotland and Northern Ireland also follow the advice below.
The aim of this guideline is to provide advice, based on clinical evidence where available, regarding the prevention of venous thromboembolism (VTE) during pregnancy, birth and following delivery. For the diagnosis and management of acute VTE in pregnancy, please refer to Green-top Guideline No. 37b: Thrombosis and Embolism during Pregnancy and the Puerperium: Acute Management.
COVID disclaimer
This guideline developed as part of the regular programme of Green-top Guidelines, as outlined in our document Developing a Green-top Guideline: Guidance for developers (PDF), and prior to the emergence of COVID-19.
Version history
This is the third edition of this guideline; the fourth edition of this guideline is currently in development.
Developer declaration of interests
Available on request.