Safety and Efficacy of Low-Molecular-Weight Heparin in Pregnant Women at Increased Risk of Venous Thromboembolism: A Prospective Stratified Multicentre Trial.

Women with a history of VTE, thrombophilia or both are at increased risk for VTE during pregnancy, but the optimal management strategy, and the need for thromboprophylaxis is not well defined in clinical guidelines because of limited trial data. The EThIG (Efficacy of Thromboprophylaxis as an Intervention during Gravidity) is a multicenter trial that prospectively enrolled 810 pregnant women at risk of VTE. Women were assigned to one of 3 management strategies: Low risk group I (including women with prior secondary VTE, or asymptomatic thrombophilia) with “watchful waiting” management, and dalteparin prophylaxis postpartum (50–100 IU/kg), or earlier if additional risk factors occurred; high risk group II (e.g. idiopathic VTE or symptomatic thrombophilia) receiving 50–100 IU/kg dalteparin; and very high-risk group III (e.g. acute VTE, prior long-term OAC, symptomatic AT-deficiency or antiphospholipid syndrome), receiving 100–200 IU/kg dalteparin. Primary efficacy outcome measure was symptomatic VTE, main safety outcome measures were haemorrhages, osteoporosis, thromboctopenia and pregnancy outcome.