The etonogestrel contraceptive implant is one of the most effective contraceptives available, with a failure rate of 0.05%. Approved for 3 years of use, it has a high 2-year continuation rate (53%–90%). Up to 11.3% of women in clinical trials discontinued use of this implant before 3 years because of bothersome bleeding (prolonged bleeding and frequent episodes).
This double-blind randomized, placebo-controlled trial was designed to determine whether 14 days of treatment with a combination of oral contraceptive pills (OCPs) would stop bleeding in users of the implant with bothersome bleeding. The OCP regimen was a low-dose combination of levonorgestrel and ethinyl estradiol. The primary study outcome was the proportion of women in each group who stopped bleeding during treatment and continued to report no bleeding at the end of 14 days of therapy. Prespecified secondary outcomes included number of days until temporary cessation of bleeding, number of days without bleeding during therapy, and number of days to recurrence of bleeding after therapy was discontinued. The investigators hypothesized that the intervention would result in temporary interruption of bleeding in 80% of the treatment group compared with 20% in the control group; using 80% power, a sample size of 26 women (13 in each group) was required. The study was performed according to the intention-to-treat principle.
Most subjects (78%) were young white women. Baseline characteristics of groups were similar. Mean age was 21 to 22 years (range, 18–44 years). A total of 66 women were screened between November 2013 and December 2014; 32 of these were randomized to an OCP group or to a placebo group. Users of the etonogestrel implant with bothersome bleeding episodes for at least 7 consecutive days were randomized to receive 14 pills of combined OCPs (150 μg levonorgestrel and 30 μg ethinyl estradiol, n = 16, or an identical-appearing placebo, n = 16).
Significantly, more women in the OCP group than in the placebo group were likely to have a temporary interruption of bleeding during the study period (14 of 16 [87.5% ± 16.2%] in the OCP group vs 6 of 16 [37.5% ± 23.7%] in the placebo group); the odds ratio was 11.7, with a 95% confidence interval of 1.9 to 70.2 (P < 0.01). Among women who had a temporary interruption of bleeding during OCP therapy, 85.7% had bleeding recurrence within 10 days after treatment ended.
Use of a low-dose combination OCP in etonogestrel implant users who had reported bothersome bleeding before treatment usually stops bleeding within 14 days. However, bleeding resumes in most patients within 10 days of treatment cessation.