Contraceptive vaginal rings releasing Nestorone® and ethinylestradiol: a 1-year dose-finding trial

Seventy-two percent of the women completed the 1-year (≥350 days) study. In studied cycles, luteal activity (progesterone ≥10 nmol/L) was noted in 17%, 7% and 12% of subjects with monitored cycles at the 150/15, 150/20 and 200/15 doses, respectively (p=.34). Two pregnancies occurred, both in subjects using the 200/15 μg/day ring. Breakthrough bleeding during ring use averaged about 2 days/year and breakthrough bleeding and spotting averaged about 7 days/year. In the entire trial, only two women discontinued because of bleeding problems. Medical conditions, chiefly vaginal problems, personal reasons and device loss or repeated expulsion were the principal reasons given for study discontinuation. Vaginal and cervical colposcopy, conducted with standardized techniques and standardized interpretations, revealed no elevated event incidence attributable to ring use. Clinical performance and adverse event profiles indicate that each of these 1-year NES/EE rings, used on a 21-day-in and 7-day-out regimen, provided women effective, acceptable and safe long-acting contraception under their own control.