[Estrogen therapy and venous thromboembolic disease].

A link between venous thromboembolism and oral contraceptive users is well established. This paper analyzes recent epidemiological studies affecting risk of venous thromboembolism with the use of oral contraceptive or with postmenopausal hormone replacement therapy. Four epidemiological studies showed a two-fold increase of venous thromboembolism with the use of oral contraceptives containing third generation progestins (gestodene and desogesterel, relative to second-generations product (levonorgestrel); relative risk 3.8 per 100,000 women years in non-user women, 16 per 100,000 women years in women using levonorgestrel containing oral contraceptive) and 29 per 100,000 women years in women using gestodene containing oral contraceptive). Third-generation oral contraceptives induce a resistance to the activated protein C of almost the same magnitude as the resistance induced by a mutation in coagulation factor V. Studies with postmenopausal estrogen-replacement therapy show a two-fold risk of venous thromboembolism with estrogen only as well as with combined estrogen-progestagen hormone replacement therapy. However venous thromboembolism risk is very small compared with the cardiovascular and other benefits.