Fertility charting is a natural and effective way to prevent pregnancy by tracking menstrual cycles and identifying the fertile window when ovulation occurs. However, it requires dedication, patience, and education to become proficient in charting and use it effectively as a form of birth control. When used perfectly, fertility awareness can be up to 99% effective at preventing pregnancy. However, with typical use, the effectiveness rate drops to around 76-88%. This is due to factors such as incorrect identification of the fertile window, inconsistent tracking of fertility indicators, failure of barrier method and unprotected sex during the fertile window. Although fertility awareness can be self taught, studies on the effectiveness of fertility awareness are performed under the guidance of a trained instructor. There is data on effectiveness of the methods which are self taught. Learning the method from a trained instructor is not strictly necessary but becomes more advisable when wanting to use fertility awareness as birth control or “trying to avoid (TTA)”. An instructor can help individuals understand the nuances of fertility charting, identify their personal patterns and indicators, and troubleshoot any issues that may arise. Instructors can also provide guidance on using fertility awareness in conjunction with other contraception methods and how to adjust the approach based on changes in health or lifestyle factors. Overall, seeking instruction and support from a trained professional can improve the effectiveness and accuracy of fertility awareness as a form of birth control.
How long does it take to learn FAM for birth control?
There is typically a three-month learning curve associated with fertility charting, during which individuals should use other contraception methods to prevent pregnancy. During this time, it’s essential to take a more conservative approach to charting and err on the side of caution when identifying the fertile window. Using a barrier method of contraception or abstaining from intercourse during the first three months of charting is essential. After the first three months, it is also advisable to use protection for the entire first half of the cycle (menstrual, follicular ovulatory phases) until 3 days after a sustained temperature rise in the luteal phase. Some more conservative methods like the Sensiplan method suggest there is a 12 month learning curve in order for the woman to chart confidently. While it is not essential for a woman to use a barrier method during the entire 12 month period, it is likely that it takes closer to 12 months to fully learn and embrace fertility awareness method.
Can I use barrier methods when practicing FAM?
Barrier methods such as condoms, female condoms or diaphragms are allowed and encouraged to be used in the fertile window to avoid pregnancy however a woman should be aware that during that time, the effectiveness of the method defaults to the effectiveness of the barrier method used. eg. condoms are 98% effective with perfect use but with typical use the effectiveness drops to 82%. In order to increase the effectiveness of the barrier method, care must be taken to use the barrier method correctly and to ensure it is not broken, faulty or expired. Depending on certain religious views, abstinence may be the only allowed choice in the fertile window. Abstinence during the fertile is more consistent with natural family planning methods that do not advocate for barrier use. This is a viable option which increases the effectiveness of FAM however its important to note that libido increases during the fertile window which makes abstinence more difficult.
How to identify the fertile window to avoid pregnancy
Charting for birth control relies heavily on correctly opening and closing the fertile window. This involves understanding the basic infertile pattern, cervical mucous and confirming ovulation with basal body temperature. Ovulation is confirmed in retrospect after 3 days of a sustained basal body temperature rise. After these three days have passed, it is safe to have unprotected sex until the arrival of the next period. The chances of pregnancy in the second half of the cycle (luteal phase) are zero. The chances of pregnancy during a period bleed and in the early follicular phase are low but not impossible depending on the timing of ovulation. A woman needs to learn her own fertility during that time based on the timing of her ovulation.
For women that struggle to open their fertile window with cervical mucous observations alone, some further calculations can be made using the Sensiplan method, which is considered the most effective FAM method for birth control based on the current research. These calculations are conservative and can offer some extra peace of mind. When beginning to chart women can make use of the Sensiplan double check method called the “plus 5 rule.” This is where the first 5 days of the menstrual cycle are assumed infertile and unprotected sex is allowed UNLESS there is observed fertile cervical mucous. Once a woman has been charting for over 12 months, she can employ the minus 8 rule. In order to do this the woman must look at her past 12 fertility charts and identify the earliest temperature rise. She can then minus 8 days from that day. All the days prior to the 8 days can be assumed infertile and unprotected sex can occur UNLESS cervical mucous is observed. These rules work best for women that do not ovulate prior to day 12 and have regular cycles. For women with irregular cycles, the single check method works best which involves simply monitoring changes to cervical mucous to open the fertile window.
To effectively use fertility charting as a form of birth control, the woman must learn to monitor fertility signs in real time and turn off any predictability function in any of the apps she may be using.
To learn more about these please read my article about getting pregnant on a period and inter menstrual bleeding here. To learn more about cervical mucous which includes information on opening and closing the fertile window and the basic infertile pattern read my cervical mucous article here: You can also read about taking basal body temperature here.