Natural Birth Control That Works
There are lots of types of natural birth controls out there, but not all work with all cycles and not all have high effectiveness rates. The Fertility Awareness Method (FAM) however, is not only up to over 99% effective when used correctly, but also works for regular cycles as well as irregular cycles.
Effectiveness of FAM
Scientific studies have found that using the Fertility Awareness Method (FAM) is as effective as the pill in preventing pregnancy when it is used correctly. According to an article published in Spring 2007 of Human Reproduction Today, when practiced properly, the effectiveness rate of FAM is 99.4%-99.6%.*
Other studies done over the years have found similar results including the World Health Organization that found FAM to be over 98% effective for avoiding pregnancy.
You may know someone who has said that they have used "natural birth control," but that does not necessarily mean they were referring to FAM. The term "natural birth control" has different meanings to different people because there are a handful of natural ways to prevent pregnancy under the umbrella term: Fertility Awareness Based Methods.
FAM is categorized as the Sympto-Thermal Method of Fertility Awareness Based Methods. This means that a person is charting their cervical fluid (symptom) against their waking body temperature (thermal) to confirm #1 when the fertile wave has begun and #2 when it has ended. Other natural family planning methods are known for only charting one sign of fertility; so charting two fertility signs is a double check that improves effectiveness. Other natural methods that predict or calculate a person's ovulation (such as the rhythm method) are also less effective in preventing pregnancy.
As with all forms of contraception, hormonal or not, there are human error factors that can influence effectiveness. Various studies show FAM user effectiveness in the high eighty-eighth percentile up to the ninetieth percentile (sometimes as low as the eightieth percentile). This is comparable to the effectiveness of other birth control methods that involve user responsibility such as the condom and oral contraceptives. Such human errors occur when the user chooses to take risks with their practice of FAM.
Studies find user effectiveness rates increase substantially when a person does not intentionally violate the method rules. Personal follow ups after the FAM workshop function to minimize unintentional errors or risks in charting and following the 4 FAM rules.
*The study linked below suggests that those who learn FAM in a workshop setting under the supervision of a qualified teacher (and receive individualized training in subsequent follow ups) maintain high user effectiveness rates. Learning from a book alone or an app alone are not necessarily considered supervised training.
*Spring 2007 Human Reproductive - Longitudinal Study: This study includes a slight variation to the method that Justina Thompson does not include in the curriculum, and therefore teaches from the strictest, meaning most conservative, version of Fertility Awareness rules . http://humrep.oxfordjournals.org/content/22/5/1310.lon