Superior cycle control with a contraceptive vaginal ring compared with an oral contraceptive containing 30 μg ethinylestradiol and 150 μg levonorgestrel:: a randomized trial

Background: This trial was conducted to compare cycle control with vaginal ring a combined contraceptive vaginal ring, and a combined oral contraceptive (COC) delivering 30 mug ethinylestradiol (EE) and 150 mug levonorgestrel. Methods: This open-label, randomized, multi-centre, Phase III study involved adult women from 11 countries. Subjects were treated with either vaginal ring or a COC for 13 cycles (12 months). Results: A total of 1030 subjects (vaginal ring, n=512; COC, n=518) comprised the intention-to-treat (ITT) population. The percentage of women in the ITT population who completed the trial was 70.9% for vaginal ring and 71.2% for the COC group. The incidence of breakthrough bleeding and spotting over cycles 2-13, the primary efficacy parameter, was lower with vaginal ring (range 2.0-6.4%) than the COC (range 3.5-12.6%), and for cycles 2 and 9 the lower incidence with vaginal ring was confirmed as statistically significant (P=0.003 and P=0.002 respectively). The incidence of intended bleeding was significantly higher over all cycles with vaginal ring (58.8-72.8%) than with the COC (43.4-57.9%). Conclusions: Cycle control with vaginal ring was excellent and superior to that of a COC containing 30 mug EE.