F5 and hereditary antithrombin deficiency: Inherited thrombophilia [factor V Leiden (FV G1691A), activated protein C resistance (APCR), prothrombin G20210A gene mutation (FII G20210A), protein C (PC) or S (PS) deficiencies or antithrombin deficiency (AT)] have all been studied in epidemiological studies exploring an association with adverse pregnancy outcomes [6].