Abstract: "Natural" methods of contraception are preferred by some halachic authorities for couples with less compelling reasons to delay pregnancy. Thus, couples may wish to use the Fertility Awareness Method. Because observant couples already abstain for a minimum of 12 days per cycle due to the rules of niddah, adjustments may have to be made in the use of this method.
FAM may be halachically recommended even when the couple is permitted to use other methods, such as spermicide or a diaphragm, in order to limit the use of these contraceptives to the times of actual fertility or together with these methods to increase the efficacy of spermicides alone.
Discussion: The Fertility Awareness Method (FAM) is a natural form of contraception based on recognizing bodily changes caused by the fluctuation of estrogen and progesterone during the menstrual cycle . When used correctly and consistently, this method enables women to identify the time surrounding ovulation when intercourse is likely to lead to conception . When trying to avoid pregnancy, a couple can use a diaphragm (if halachically approved) during this fertile period or abstain. FAM techniques can also be used for the opposite purpose, to optimize chances of conception when a couple is trying to achieve pregnancy .
FAM is often confused with the ineffective rhythm method , which uses mathematical calculations based on past cycle lengths to predict infertile days for the present cycle . FAM relies only on daily observation of fertility changes in the present, and is therefore more accurate and effective . Couples choose this method because it eliminates the side effects of hormonal contraceptives ,  and avoids the inconvenience of staining which can occur with IUDs .
FAM is based on the following scientific principles :
- Hormonal fluctuation causes recognizable changes in basal body temperature, consistency of cervical fluid  and the position of the cervix.
- The ovum lives only 12-24 hrs ,
- Sperm can live for more than 3 days in fertile-quality secretions , and
- The corpus luteum inhibits further ovulation from about 24 hours after ovulation for about two weeks .
To apply this method, women monitor the following:
Basal Body Temperature (BBT) - Oral temperature is taken each morning after a night's rest of at least 3 hours and charted. A consistent rise means that ovulation has taken place. Once this rise is verified, a woman is no longer fertile for the rest of the cycle .
Cervical Secretions are checked prior to urination throughout the day. This is generally done at the vaginal opening. Cervical secretions change through out the cycle in response to the hormonal changes of the cycle . The cervical mucous differs slightly between the follicular and luteal phases. During the follicular phase it tends to be clear, thin, and watery and typically not very noticeable to the woman. At ovulation the secretions become milkier, wetter, and thinner, and resemble egg-white. The progesteronal effect on cervical mucous during the luteal phase makes it thick, yellow, creamy, or even crusty or green.
Changes in Cervical Position occur only at the time of ovulation . By inserting a finger deep in the vagina, a woman can recognize the changes before, during, and after ovulation. On infertile days, the cervix is lower, closed, and hard. At ovulation it moves upwards towards the uterus, opens, and softens. This is the only fertility sign that requires internal checking.
A woman can decide whether to chart one, two, or all three fertility signs. The more signs she checks, the more reliable the outcome and the more confidence she will feel in applying the method . Charting initially requires 1-2 minutes per day. After two learning sessions and 2-3 practice cycles, most women are able to interpret their fertility signs independently. In order to be effective, FAM should be learned with a qualified teacher .
Avoiding relations during the fertile period (which, for the observant couple, means only the post ovulatory phase) can shorten the time available to the couple for marital relations (depending on the woman's cycle length). In particular, mikveh night, when it is considered a mitzvah to have relations, often falls during the fertile period. Some rabbinic authorities allow the woman to immerse for the purpose of physical contact and closeness without intercourse. Others recommend that the couple delay mikveh immersion.
Although FAM is a 'natural' method and involves no external intervention, it is still a form of birth control. FAM may be used for contraception only where the couple is halachically permitted to delay pregnancy.
FAM may be halachically recommended even when the couple is permitted to use other methods, such as spermicide or a diaphragm, in order to limit the use of these contraceptives to the times of actual fertility.
The book Taking Charge of Your Fertility, by Toni Weschler MPH, while written for a lay audience, is well referenced and is a good resource on the medical aspects of this method even for the health professional.
Implications for Patient Care: Some couples may wish to use the Fertility Awareness Method, either fully or partially. Therefore, practitioners should be aware of this method in order to best advise their patients as to how it works and whether it is sufficient for their contraceptive needs, and to refer them to appropriate educator. The days available for intercourse will be fewer than in the general population due to the limitations of the laws of niddah.
 Clubb E. Natural methods of family planning. J R Soc Health 1986 Aug;106(4):121-6.
 Guida M, Tommaselli GA, Pellicano M, et al. An overview on the effectiveness of natural family planning. Gynecol Endocrinol 1997;11:203.
 Stanford JB, White GL, Hatasaka H. Timing intercourse to achieve pregnancy: current evidence. Obstet Gynecol 2002 Dec;100(6):1333-41.
 Stanford JB, Thurman PB, Lemaire JC. Physicians' knowledge and practices regarding natural family planning. Obstet Gynecol 1999 Nov;94(5 Pt 1):672-8.
 Kambic R, Lamprecht V. Calendar rhythm efficacy: a review. Adv Contracept 1996;12:123-28.
 Clubb, E, Knight, J. Fertility: Fertility Awareness and Natural Family Planning. Devon: David & Charles, 1996.
 Rosenberg MJ, Waugh MS, Meehan TE. Use and misuse of oral contraceptives: Risk indicators for poor pill taking and discontinuation. Contraception 1995 May;51(5):283-8.
 Further analyses of mortality in oral contraceptive users. Royal College of General Practitioners' Oral Contraception Study. Lancet 1981;1:541.
 Mechanism of action, safety and efficacy of intrauterine devices. Report of a WHO Scientific Group. World Health Organ Tech Rep Ser 1987;753:1.
 Pyper CM, Knight J. Fertility awareness methods of family planning: the physiological background, methodology and effectiveness of fertility awareness methods. J Fam Plann Reprod Health Care 2001 Apr;27(2):103-9.
 Alliende ME, Cabezon C, Figueroa H, Kottmann C. Cervicovaginal fluid changes to detect ovulation accurately. Am J Obstet Gynecol 2005;193:71.
 Speroff L, Fritz MA. Clinical Gynecologic Endocrinology and Infertility. 7th ed. Baltimore: Lippincott Williams & Wilkins, 2005;217-218.
 Marshal J. A field trial of the basal body temperature method of regulating births. Lancet 1968;ii:8-10.
 Keefe E. Cephalad shift of the cervix uteri: Sign of the fertile time in women. International Review of Natural Family Planning 1977;1(1):55-60.
Users of Internet filtering services: This site discusses sensitive subjects that some services filter without visual indication. A page that appears 100% complete might actually be missing critical Jewish-law or medical information. To ensure that you view the pages accurately, ask the filtering service to whitelist all pages under jewishwomenshealth.org.