Risk of venous thromboembolism during pregnancy and birth

Venous thromboembolism (VTE) is the leading cause of direct maternal deaths in the UK (Royal College of Obstetricians and Gynaecologists (RCOG), 2015). A report published by MBRRACE-UK (Mothers and Babies: Reducing Risk through Audits and Confidential Enquiries across the UK) found that 30 out of 252 maternal deaths between 2009 and 2011 were attributed to VTE: 1.26 per 100 000 maternities (Knight et al, 2014). This mortality rate is more than double that attributed to haemorrhage, and almost three times that of pre-eclampsia and eclampsia.

This finding is not new. Confidential enquiry historical data prior to 2006 demonstrate that VTE has been the main direct cause of maternal deaths since 1985. In 2006–2008, VTE dropped to third place in the list of the most common causes of maternal death (0.79 per 100 000), behind genital sepsis, pre-eclampsia and eclampsia. Although there is no significant statistical difference between the change in the mortality rate of VTE over time, there have been improvements in the survival rates for other causes of maternal death, therefore VTE has returned as the leading direct cause of death in pregnant women. These figures, however, do not account for the large number of women who survive a VTE episode but go on to have a morbidity later in life.