Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 26 3-4 1997 09 15 25 34 H.R. Sadeghipour Roudsari M. Faghihi 2015 10 03 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 https://ijph.tums.ac.ir/index.php/ijph/article/view/1800 https://ijph.tums.ac.ir/index.php/ijph/article/download/1800/1781