<prompt> Which is associated with ed risk of Thrombo-embolism in a normal pregnancy:ed progesterone leveled production of clotting factors by liverChange in blood viscosityed antithrombin III  <response>: Stasis, Hypercoagulability and vascular trauma Virchows triad occurs in pregnancy and thus increases the risk of thrombsosis. Hypercoagulability is due to: Increase in Fibrinogen, prothrombin and factors VII,VIII,IX X Decrease in levels of protein S. Resistance to activated protein C. Increase in levels of antifibrinolytic Types 1 2, plasminogen activator inhibitor PAI type 1 2. The net result is reduction in the risk of antepaum, intrapaum and postpaum hemorrhage but also a dramatic 10 fold increase in the pregnancy associated thromboembolism. 