Bleeding profile associated with 1-year use of the segesterone acetate/ethinyl estradiol contraceptive vaginal system: pooled analysis from Phase 3 trials

Abstract

Objectives: To describe bleeding patterns among users of the segesterone acetate (SA) and ethinyl estradiol (EE) contraceptive vaginal system (CVS), and identify factors associated with unscheduled bleeding/spotting (B/S).

Study design: We pooled results from two multicenter, single-arm, open-label, pivotal, phase 3 studies of the SA/EE CVS conducted in 17 US and 7 international sites. Participants (age 18-40 years; BMI ≤29 kg/m²) followed a 21/7-day in/out schedule of CVS use for up to 13 cycles and recorded vaginal bleeding daily in paper diaries. Scheduled and unscheduled B/S were summarized by cycle. We used multiple logistic regression to identify factors associated with unscheduled bleeding/spotting, based on the first 4 cycles only.

Results: Analysis included data from 2070 participants (16,408 cycles). Ninety-eight percent documented scheduled B/S [mean (SD): 4.9 (1.1) days/cycle)]. Absence of scheduled B/S was 5-8% of women/cycle. Unscheduled B/S ranged from 13.2% to 21.7% of women per cycle. Few women (1.8%) discontinued prematurely due to unacceptable bleeding. Black women were more likely to report unscheduled B/S than White women [Adjusted odds ratio (AOR) = 1.49, 95% confidence interval (CI) = 1.14-1.94]. Women with fewer years of schooling [<high school (AOR=0.62, 95% CI=0.43-0.90); high school graduate (AOR: 0.76, 95% CI=0.60-0.97)] were less likely to report any episode of unscheduled B/S compared to college graduates.

Conclusions: Participants using the SA/EE CVS up to 13 cycles reported good cycle control. Discontinuation due to unacceptable bleeding was very low. Further research into demographic/other differences with reported unscheduled bleeding is warranted.

Implications: Since good cycle control is a key factor influencing contraceptive selection, adherence and continuation of combined hormonal contraceptives, the favorable bleeding profiles experienced by women during the SA/EE CVS clinical trials provide reassuring information for prospective users.

Trial registration: ClinicalTrials.gov NCT00263341 NCT00455156.

Keywords: Bleeding patterns; Combined hormonal contraceptives; Contraceptive vaginal system; Nestorone; Segesterone acetate.