Objective: To compare the bleeding patterns and tolerability of 3 different extended ring regimens with those of the standard 28-day cycle with 21 days of contraceptive vaginal ring use followed by 7 ring-free days.
Methods: Following a run-in 28-day ring cycle, women were randomized to 1 of 4 regimens: monthly (28-day cycle), every other month (49-day cycle), every third month (91-day cycle), or continuous (364-day cycle). Treatment duration was 1 year. Daily bleeding diary, interval visit questionnaire, and examination data were collected.
Results: A total of 561 women were enrolled, 429 were subsequently randomized, and 289 (67.4%) women completed the entire year. All schedules were well tolerated and acceptable to women, but study completion rates were higher for the shorter cycles. Bleeding days were reduced with postponement of the withdrawal bleeding (ring-free) week, but spotting days increased. For example, women using the continuous or 364-day ring cycle reported a median of zero bleeding days but 10-12 days of spotting during the first 3 months of extended use. Unscheduled bleeding during ring use was the lowest with the traditional 28-day cycle. Adverse events, blood pressure, body weight, and laboratory findings were comparable over the 4 treatment groups.
Conclusion: The combination vaginal contraceptive ring can be used for extended cycles to alter the bleeding schedule. Women willing to tolerate some spotting might choose the longer extensions to have fewer menstrual periods.
Level of evidence: I.