Risk of venous thromboembolism with third-generation oral contraceptives: A review.

Recent data indicate that users of third-generation oral contraceptives, those containing the new progestins desogestrel, gestodene, and norgestimate, have 2 to 3 times the risk of venous thromboembolism faced by users of second-generation oral contraceptives. The risk of development of deep vein thrombosis was also found to be 2 to 5 times greater with a low-estrogen, desogestrel-containing oral contraceptive than with second-generation monophasic and triphasic preparations. Investigators point to an acquired resistance to the anticoagulation effects of activated protein C, the most common cause of hereditary thrombophilia, as a possible mechanism. The American College of Obstetrics and Gynecology's Committee on Gynecologic Practice reconfirms the increased risk of venous thromboembolism associated with third-generation progestins versus other progestins. Because the third-generation oral contraceptives may have benefit for some patients, however, it defers to the individual clinician's and patient's judgment regarding the use of a desogestrel-containing formulation (the only third-generation progestin available in the United States).