From the Guidelines
Natural Cycles, a hormone-free birth control method, has a typical use effectiveness rate of around 76-88%, meaning 12-24 women out of 100 may become pregnant in a year, as it relies on tracking fertility signs to identify fertile days and avoid intercourse or use barrier methods during those times 1.
Effectiveness of Natural Cycles
The effectiveness of Natural Cycles as a form of contraception is moderate, with a higher failure rate when not used perfectly.
- When used perfectly, Natural Cycles have about a 95-99% effectiveness rate, but with typical use, effectiveness drops to around 76-88% 1.
- This method works by tracking fertility signs like basal body temperature, cervical mucus changes, and menstrual cycle patterns to identify fertile days when pregnancy is most likely to occur 1.
- Users then avoid intercourse or use barrier methods during fertile periods, requiring daily monitoring, careful record-keeping, and periods of abstinence or backup contraception 1.
Important Considerations
- Natural methods provide no protection against sexually transmitted infections, so condoms would be needed for STI prevention 1.
- These methods are most suitable for women with regular cycles who are comfortable with their bodies, willing to track fertility signs daily, and able to abstain or use backup methods during fertile periods.
- Women using Natural Cycles should receive proper training from a healthcare provider, maintain regular cycles, and be highly motivated to follow the method precisely for best results 1.
From the Research
Effectiveness of Natural Cycles as a Form of Contraception
- The effectiveness of Natural Cycles, a hormone-free birth control method, has been studied in several research papers 2, 3, 4, 5, 6.
- A study published in 2021 found that the Natural Cycles app had a 13-cycle cumulative pregnancy probability of 7.2% and a 1-year typical use Pearl Index (PI) of 6.2 2.
- Another study published in 2019 found that the typical use 1-year Pearl Index (PI) of Natural Cycles varied depending on the user's previous choice of contraceptive, ranging from 3.5±0.5 for women who had used condoms before to 8.1±0.6 for women who had used the pill before 3.
- A study published in 2017 found that the Natural Cycles application had a typical-use Pearl Index of 6.9 pregnancies per 100 woman-years and a perfect-use Pearl Index of 1.0 pregnancy per 100 woman-years 6.
- The effectiveness of Natural Cycles is influenced by factors such as the user's previous contraceptive choice and their motivation and commitment to using the method correctly 3, 4.
- Compared to traditional fertility awareness-based methods, the efficacy of the Natural Cycles mobile application is higher, with a typical-use failure rate of 8.3% and a perfect-use failure rate of 1.0% 6.
Comparison to Other Contraceptive Methods
- Natural Cycles has been compared to other contraceptive methods, including hormonal birth control and condoms, in terms of its effectiveness and user satisfaction 3, 5.
- A study published in 2016 found that only some fertility awareness-based method apps, including Natural Cycles, use evidence-based methods and have rates of effectiveness similar to those of commonly used forms of hormonal birth control 5.
- The Natural Cycles app has been shown to be an effective form of contraception, with a lower typical-use failure rate than some other methods, such as condoms 3.
User Characteristics and Behavior
- The demographics of Natural Cycles users have been studied, with one study finding that the average user is 30 years old with a body mass index of 24 and is in a stable relationship 2.
- User behavior, such as the frequency of unprotected sex on fertile days, can affect the effectiveness of Natural Cycles 3.
- The discontinuation rate of Natural Cycles has been estimated to be around 54% over 12 months, highlighting the importance of user motivation and commitment to using the method correctly 6.