Please note: This archive was last updated in 2005.

RHO archives : Topics : Contraceptive Methods

Natural Family Planning


Natural family planning, also called periodic abstinence, requires users to practice abstinence during the fertile period of a woman's menstrual cycle. Clients using natural family planning may use one technique or a combination of techniques to identify the start and end of a woman's fertile period. Natural family planning can be very effective when clients are properly trained and counseled and when they are motivated to avoid unprotected intercourse for a week or more each month. For other women, however, failure rates can be quite high. The method has no side effects. No medical condition restricts a client's eligibility for use of the method.

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Characteristics of natural family planning


2% to 30% failure rate during first year of use; depends on a woman's ability to identify the fertile period of each menstrual cycle and couples' motivation and discipline to practice abstinence when required.

Age limitations

No restrictions.

Parity limitations

No restrictions.

Mode of action

Helps a client prevent pregnancy by avoiding unprotected sexual intercourse during the fertile period of a woman's menstrual cycle.

Effect on STI risk

Not protective.

Drug interaction


Duration of use

Most women can use natural family planning safely throughout their reproductive years (if they are satisfied with the method and have no problems with it).

Return to fertility

Immediately upon discontinuation.

Recent innovations

Recent tested innovations in Natural Family Planning include the Standard Days Method (SDM) and the Two-Day Method, both designed to make natural family planning easier to use for planning or avoiding pregnancy. (Also see the description of Georgetown Institute for Reproductive Health.)

The Standard Days Method is a simple calendar-based method in which users are counseled to abstain from unprotected intercourse on days 8 through 19 of any cycle to avoid a pregnancy. The method is based on recent research that identifies more precisely when a woman is most likely to become pregnant. The concept sought to identify a fixed "window" of fertility, which makes it easier for women to know when during their menstrual cycle they are likely to become pregnant, and when they therefore should not have unprotected intercourse if they want to avoid a pregnancy. This method is simple for service providers to teach and for women to use because there are no calculations or sympto-thermal observations involved. The Georgetown Institute for Reproductive Health describes the advantages and disadvantages of this method, findings from recent studies of acceptability of this method, and program ideas for incorporating this method into a family planning program (GIRH 2004).

The Two-Day Method of natural family planning is based on the identification of the fertile days by monitoring the presence or absence of cervical secretions during the menstrual cycle. This method is grounded in research completed over the last several years on the relationship of fertility signs to actual fertility as well as recent work that more precisely delineates the fertile days of the cycle.   

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