Pregnant women and post-partum women are generally in a hypercoagulable state [25] and at an increased risk for thrombo-embolic events altogether [26, 27] due to elevated levels of factors VII, X, VIII, fibrinogen, and von Willebrand; an increase in prothrombin fragments and thrombin-antithrombin complexes; a reduction in protein S activity; and an acquired activated protein C resistance [28]. Here, PROS1 is linked to thrombophilia.