Efficacy and safety of a 28-day oral contraceptive with 7 days of low-dose estrogen in place of placebo

BackgroundThe study was conducted to evaluate the efficacy and safety for the prevention of pregnancy of a 28-day oral contraceptive (OC) containing 150 mcg desogestrel (DSG)/20 mcg ethinyl estradiol (EE) for 21 days followed by 7 days of 10 mcg EE (Cette-28).Study DesignA 6-month, prospective, multicenter, single-arm study was conducted in 1302 women aged 18–45 years.ResultsOver six cycles of treatment, the cumulative risk of pregnancy among all treated subjects (n=1262) was 0.9%. The Pearl Index for women 18–35 years of age (n=1042) was 2.20, including 9 pregnancies with estimated conception dates during active drug ingestion or up to 7 days after the last combination tablet. The rate of unscheduled bleeding was low and the duration of scheduled bleeding was approximately 2 days during each of the six treatment cycles. The safety profile was similar to what has been reported for other OCs.ConclusionThis low-dose, 28-day OC incorporating 7 days of 10 mcg EE during the hormone free interval is effective and safe for the prevention of pregnancy and is well-tolerated by women.