effect of oral contraceptives (ld and cilest) on clotting factors viii and ix

based on epidemiologic data, women who take oral contraceptives seem to have an increased risk of developing thromboembollic disease. the thrombotic effects of oral contraceptive (oc) are probably mediated, at least partly through their effects on the coagulation system. plasma levels of several clotting factors have been shown to be elevated in oc users, and this increase is graduated according to the dose of estrogen. in this study, fifty healthy and non smoking women, aged 18-35 years, were randomly assigned to treatment with 2 different ocs: a monophasic pill containing 30 pg of ethinyl estradiol plus 150µg levonorgestrel (ld) and a monophasic pill containing 35µg ethinylestradiol plus 250pg norgestimate (cilest). factor viii plasma values were significantly decreased (p<0.05) only in women treated with the preparation ld, but the levels of factor viii were not significantly different in the group treated with cilest. factor ix plasma values were significantly increased (p<0.05) only in women treated with the preparation cilest, but the levels of factor ix were not significantly different in the group treated with ld. in ld and cilest users factors viii and ix were not significantly changed (p<0.05) in overweight and obese subjects in comparison to normal weight.