Abstract
Venous thromboembolism (VTE) continues to pose significant maternal and fetal risks in pregnancy. When compared to nonpregnant women not using contraception, the risk of VTE rises exponentially as pregnancy progresses. Substantial changes must occur in local (decidual) and systemic coagulation, anticoagulant, and fibrinolytic systems to meet the hemostatic challenges of pregnancy. During pregnancy, hormonal changes, specifically increases in estrogen and progesterone, lead to a transient hypercoagulable state. Vascular stasis, hypercoagulability, and vascular trauma remain the three prime antecedents to thrombosis. Pregnancy‐associated deep venous thrombosis (DVT) is more often proximal and massive than in the nonpregnant setting and usually occurs in the left lower extremity. The occurrence of a thromboembolic event, even in pregnant women with an inherited thrombophilia, is highly dependent on other predisposing risk factors such as immobility, obesity, surgery, infection, etc. Venous ultrasound with or without color Doppler is the primary diagnostic modality for evaluating patients at risk of DVT.