HEMOSTASIS PROFILE IN SMOKING AND NONSMOKING WOMEN TAKING LOW-DOSE ORAL-CONTRACEPTIVES

The effects of oral contraceptives on coagulation in 258 nonsmoking an d in 190 smoking women were determined. In smokers and in nonsmokers t aking oral contraceptives, fibrinogen and fibrinopeptide A concentrati ons were higher than in oral contraceptive nonusers. In nonsmokers, or al contraceptives increased antithrombin III activity. The effects on coagulation of oral contraceptives with a different ethinylestradiol c ontent (from 35 mcg to 20 mcg) were then evaluated in 333 of these wom en. The biggest changes in coagulation were observed in smokers taking the preparation with the highest estrogen content. Reduction of the e thinylestradiol dose caused a decrease of the changes in coagulation i nduced by oral contraceptives both in smokers and nonsmokers. These re sults might suggest that during oral contraception the coagulation sys tem is affected mainly in smokers and that the decrease of the estroge n dose might lower the effects of the association of smoking and oral contraception on coagulation.