[Evaluation of some blood clotting parameters in relation to the administration of estroprogestins].

A number of blood clotting parameters have been determined in the plasma of 25 women who had not previously taken steroid contraceptives. After the administration of an oestroprogestinic association (ethynyloestradiol 0.05 mg + norgestrol 0.25 mg) for five cycles, the same subjects were controlled again for the determination of the same haematochemical parameters. The changes observed highlighted a marked increase in fibrinogenaemia and fibrinolysis, a slight rise in associated clotting factors II-VII-X, no change in the activity of antithrombin III and platelet aggregation.