TF and venous thromboembolism: When compared to drug-naive PCOS women, OCP users had significantly higher plasma levels of clotting factors such as tissues factor (TF), factor XIa, tissue plasminogen activator (tPA), factor Va, D-dimer and thrombin antithrombin (TAT) III complex values, as well as statistically significant lower prothrombin time (PT) and activated partial thromboplastin time (APTT) values, implying that the drug's interaction with various metabolic pathways raises the risk of hypercoagulability, venous thromboembolism and thrombotic events [24, 25].