Efficacy, cycle control, and user acceptability of a novel combined contraceptive vaginal ring.

Objective: To assess the contraceptive efficacy, cycle control, tolerability, and user acceptability of a novel combined contraceptive vaginal ring for up to 13 cycles.

Methods: Healthy women requesting contraception were enrolled in this 1-year multicenter study. Each ring released 120 microg of etonogestrel and 15 microg of ethinylestradiol daily, and was used for 3 weeks followed by a 1-week ring-free period.

Results: A total of 2322 women started treatment and so formed the intent-to-treat population. Subjects were followed for 23,298 cycles, equivalent to 1786 woman-years. Compliance was good with 85.6% of cycles in full compliance with specified criteria. In the intent-to-treat population, 21 pregnancies occurred, giving a Pearl Index of 1.18 (95% confidence interval 0.73, 1.80). Eleven of the pregnancies were attributable to noncompliance; the Pearl Index for the per-protocol population was 0.77 (95% confidence interval 0.37, 1.40). The mean incidence of withdrawal bleeding was 98.5% in all cycles. Irregular bleeding occurred in 5.5% of all cycles, and in most women, early or late withdrawal bleeding was restricted to spotting. The ring was well tolerated with a low incidence of adverse events; only 2.5% of all discontinuations were device related. The ring was easy to insert and remove and did not interfere with intercourse. Eighty-five percent of women were satisfied with the ring, and 90% would recommend its use to others.

Conclusion: The ring is an effective contraceptive with excellent cycle control that is convenient, well tolerated, and highly acceptable to users.