Extended-cycle versus conventional treatment with a combined oral contraceptive containing ethinylestradiol (30 μg) and levonorgestrel (150 μg) in a randomized controlled trial.

The objective was to assess efficacy and safety of a combined oral contraceptive containing ethinylestradiol (EE) and levonorgestrel (LNG) in an extended-cycle vs. a conventional-cycle regimen. This first European randomized, active controlled, open, prospective, parallel-group trial was conducted in 48 German gynecological centers. 1,314 healthy, sexually active women aged 18-35 years were randomized. With an unadjusted PI of 0.483 (upper 95% CI: 1.237), the extended-cycle regimen fulfilled the contraceptive efficacy of EE/LNG, the requirements of the European Medicines Agency. The mean total number of bleeding days per year was significantly lower in the extended-cycle vs. the conventional-cycle regimen. Analyses of bleeding patterns showed a reduced total number of bleeding/spotting days per year in the extended-cycle vs. the conventional-cycle regimen. Cycle-associated complaints and AE were comparable in both groups. Both regimens were very well accepted. The extended-cycle regimen of EE/LNG was effective and well tolerated resulting in a lower number of bleeding days and a favorable bleeding pattern compared to the conventional-cycle regimen.