The risk of venous thromboembolism in early pregnancy loss: Review of the literature and current guidelines and the need for guidance - Communication from the SSC on Women's Health Issues for thrombosis and haemostasis

Background: Thromboembolic disease is one of the major causes of mortality and morbidity in pregnancy and the puerperium, with 1 death per 100 000 births attributed to venous thromboembolism (VTE). Factors associated with development of thrombosis are all present in pregnancy, with some of these changes seen from conception.

Objective: Given how common early pregnancy loss is, the aim of this review is to evaluate the uncertainty surrounding the risk of VTE following early pregnancy loss and termination of pregnancy.

Methods: A structured literature search was conducted to identify existing evidence as well as international pregnancy-specific guidelines regarding assessment and prevention of VTE risk in pregnant women. This review was reviewed, critiqued, and approved by all members of the International Society on Thrombosis and Haemostasis subcommittee for Women's Health Issues in Thrombosis and Haemostasis.

Results: Four published original research studies, one clinical comment paper, and six guidelines were reviewed. Despite clear evidence of the increased risk of VTE in pregnancy, there is a lack of guidance regarding evaluation and management after early pregnancy loss.

Conclusion: International collaborative research to determine the risk of VTE and its prevention in women undergoing surgical termination of pregnancy or following surgical management of early pregnancy loss is urgently needed. Pregnancy-specific risk assessment taking into account preexisting risk factors is advocated. Education of health care professionals involved in early pregnancy care and guidance on management, albeit based on limited existing evidence, are necessary to highlight the need for individualized care.