Clinical Study III - Effectiveness of Natural Cycles

The largest prospective study carried out on Natural Family Planning
Having studied over 22’785 women, who were 29 years of age on average, and analyzed 224'563 menstrual cycles this is the largest prospective study carried out not only on Natural Cycles but on natural contraception as of yet. It demonstrates the efficacy of Natural Cycles as a method of contraception by analyzing women’s real-life data. The results clearly show that the app’s efficacy is higher than typically reported for traditional fertility awareness-based methods (75%).

The study has shown that Natural Cycles has a perfect use failure rate of 1.0, which means that 1 out of 100 women who use the app for one year may become pregnant, either due to method failure i.e. the app wrongly attributing a green day or the chosen method of contraception on a red day having failed. The app has a typical use failure rate of 6.8, which means that in total 6.8 women out of 100 may get pregnant during one year of use due to all possible reasons (e.g. having unprotected intercourse on red days). The resulting efficacy rate for perfect use is 99% and for typical use is 93%.

To break it down into the numbers:
- Typical use 6.8
- Perfect use: 1.0
- Method failure rate: 0.5