Thrombosis in pregnancy

Pregnancy and the puerperium are associated with a 10-fold increase in the risk of venous thromboembolism, comprising deep vein thrombosis and pulmonary embolism, compared to the non-pregnant state. Pulmonary embolism has been the leading direct cause of maternal mortality in most of the United Kingdom’s triennial Confidential Enquiries into Maternal Deaths over the past 30 years, attesting to the importance of prevention and prompt diagnosis and treatment of venous thromboembolism during pregnancy and following delivery. The diagnosis of venous thromboembolism is challenging in pregnancy because it can be difficult to distinguish features of venous thromboembolism, such as leg swelling and breathlessness, from those of normal pregnancy, and there are no validated clinical scoring systems. All women should undergo risk assessment for venous thromboembolism in early pregnancy, at the time of hospital admission or change in clinical condition, and after delivery.