Prevention of venous thromboembolism in pregnancy.

Venous thromboembolic complications (VTE) are a leading causes of maternal mortality in the developed World. To reduce the incidence VTE in pregnancy, and improve outcomes, a wider understanding of the risk factors involved and a better identification of women at risk of thrombosis coupled with effective thromboprophylaxis are required. The common risk factors for VTE in pregnancy are: age over 35 years; obesity; operative delivery (especially emergency Caesarean Section in labour); thrombophilia; and a family or personal history of thrombosis suggestive of an underlying thrombophilia. As warfarin is unsuitable for use in pregnancy because of problems with embryopathy and risk of fetal bleeding, optimal thromboprophylaxis in pregnancy centres on the use of low-molecular-weight heparin (LMWH). There is now extensive experience of the safety and efficacy of LMWH in pregnancy. LMWH's, such as enoxaparin and dalteparin, have clinical and practical advantages compared with unfractionated heparin in terms of improved safety (significantly lower incidence of osteoporosis and heparin induced thrombocytopenia), and patient convenience with once daily dosing for the majority of women. Thus LMWH is now the agent of choice in pharmacological thromboprophylaxis in pregnancy