Methods

Symptoms-based

Main article: Fertility awareness

Some methods of NFP track biological signs of fertility. When used outside of the Catholic concept of NFP, these methods are often referred to simply as fertility awareness-based methods rather than NFP.^[33] The three primary signs of a woman's fertility are her basal body temperature, her cervical mucus, and her cervical position.^[34] Computerized fertility monitors may track basal body temperatures, hormonal levels in urine, changes in electrical resistance of a woman's saliva or a mixture of these symptoms.^[35]
From these symptoms, a woman can learn to assess her fertility without use of a computerized device. Some systems use only cervical mucus to determine fertility. Two well-known mucus-only methods are the Billings ovulation method and the Creighton Model FertilityCare System. If two or more signs are tracked, the method is referred to as a symptothermal method. Two popular symptothermal systems are taught by the Couple to Couple League and the Fertility Awareness Method (FAM) taught by Toni Weschler.^[36] A study completed in Germany in 2007 found that the symptothermal method has a method effectiveness of 99.6%.^[37]
In Canada, the symptothermal method is taught by SERENA Canada which is an inter-denominational organization which has been developing the Symptothermal Method as a part of NFP since 1955. They are also not specifically affiliated with the Roman Catholic Church. It is also taught by Justisse Healthworks for Women, a pro-choice feminist organization that allows and supports women to combine other methods of birth control with their fertility awareness practice.

[edit] Calendar-based

Main article: Calendar-based methods

Calendar-based methods determine fertility based on a record of the length of previous menstrual cycles. They include the Rhythm Method and the Standard Days Method. The Standard Days method was developed and proven by the researchers at the Institute for Reproductive Health of Georgetown University. CycleBeads, unaffiliated with religious teachings, is a visual tool based on the Standard Days method. According to the Institute of Reproductive Health, when used as birth control, CB has a 95% effectiveness rating. iCycleBeads is the first iPhone app based on a natural family method, Standard Days. Women can plan or prevent pregnancy naturally via their iPhone or Apple brand device.^[38]

[edit] Lactational amenorrhea

Main article: Lactational amenorrhea method

The lactational amenorrhea method (LAM) is a method of avoiding pregnancy based on the natural postpartum infertility that occurs when a woman is amenorrheic and fully breastfeeding. The rules of the method help a woman identify and possibly lengthen her infertile period. A strict version of LAM is known as ecological breastfeeding.