Robert W. Rebar, MD

During routine use, vaginal rings and combined oral contraceptive pills had similar venous and arterial thromboembolic risk profiles.

Surveillance of cardiovascular risk associated with routine use of hormonal contraception can help assure short- and long-term safety. In a manufacturer-funded, prospective cohort study at 1661 centers in the U.S. and five European countries, investigators evaluated the medical records of 16,864 women who were new users of a contraceptive vaginal ring (15 µg ethinyl estradiol and 120 µg etonogestrel released daily for 21 days each month) compared with 16,431 new users of combined oral contraceptive pills (OCPs). Only 3% of subjects were lost to follow-up during the 4-year study.

In all, 57 venous thromboembolic events (including 13 pulmonary emboli) and 17 arterial thromboembolic events were documented, with similar incidence in the two cohorts. Adjusted hazard ratios for vaginal ring users compared with OCP users were 0.8 for venous thromboembolism and 0.7 for arterial thromboembolism. These findings did not change when users of OCPs without desogestrel, gestodene, or drospirenone were excluded.

Citation(s):

Dinger J et al. Cardiovascular risk associated with the use of an etonogestrel-containing vaginal ring. Obstet Gynecol 2013 Oct; 122:800.