Although the use of oral contraceptives has been frequently associated with an increased
risk of thromboembolic events, definitive prothrombotic mechanisms have not so far been
fully elucidated. The aim of our investigation was the evaluation of the activities of
antithrombin, protein C, protein S and the resistance to activated protein C in 137 healthy
users of third-generation oral contraceptives and in 170 healthy women who were not
consuming oral contraceptives. Women on oral contraceptives showed a marked …