ABSTRACT
As compared with nonpregnant women of childbearing age, in whom the risk is very low, the risk of venous thromboembolism during pregnancy is increased about five fold, with an incidence of 1-2 per 1000 pregnancies. Increased venous stasis, venous
compression by the gravid uterus, and alterations in the proteins of the coagulation and fibrinolytic systems all play a part in increasing the risk. The risk is spread throughout pregnancy and for several weeks postpartum, with venous thrombosis being more common before delivery and pulmonary embolism postpartum.