For couples who want a contraceptive method that is user-controlled and free from side effects, natural family planning may be an option. Couples seeking very reliable contraception who may have difficulty using this method correctly all of the time, however, should consider alternate methods. Also, women with conditions where unintended pregnancy may be an unacceptable risk should consider using more effective or permanent methods.
Natural family planning (NFP) requires couples to recognize normal physiological changes that indicate a woman is ovulating and to avoid sexual relations around this time. In order to practice NFP effectively, couples must understand that men are fertile all the time but that women are fertile only a few days a month, around the time of ovulation (when the egg is released from the ovary); that ovulation occurs around the midpoint of a woman's menstrual cycle (about 14 days before or after menstrual bleeding); and that ovulation can be confirmed by a rise in a woman's temperature, as well as changes in the consistency of her cervical mucus. To prevent pregnancy, couples avoid intercourse during the fertile time, a practice called "periodic abstinence."
"Certainly, if you avoid sex during the fertile days of the menstrual cycle, you will not get pregnant," says Dr. Roberto Rivera, FHI's corporate director of international medical affairs. "But many couples do not have the discipline to examine fertility signs daily or to abstain from intercourse when they should do so. These couples should be encouraged to consider other methods."
"The issues with NFP are both technical and behavioral," says Dr. Carlos Huezo, medical director of the International Planned Parenthood Federation (IPPF) in London. "For those who cannot master the techniques of identifying the fertile phase and who cannot practice abstinence, the rates of pregnancy can be extremely high."
Some providers note that the signs women use to predict fertility may not be reliable, since they can be altered by a variety of physical or emotional factors, such as illness or stress. This and other factors can reduce effectiveness. While pregnancy rates for perfect use of some NFP methods can be under 3 percent, the rate for typical use is about 20 percent during the first year, comparable to rates for typical spermicide or diaphragm use.1
A recent study by the National Family Planning Board of Jamaica found that 12 percent of private physicians opposed NFP.2 A survey of 375 physicians in Mauritius, Sri Lanka, the Philippines and Peru found that nearly half said they would not recommend periodic abstinence to their clients.3 In Sri Lanka, physicians who recommended methods involving periodic abstinence were more likely to have used the methods themselves.4
Adequate training to help couples identify fertility signs, and counseling about the need for abstinence during "unsafe" days, are important elements for achieving effective use of the method. "If NFP methods are well-taught and well-practiced, they are very effective -- not as effective as provider-controlled methods but as effective as other client-controlled methods," says Dr. Victoria Jennings of the Institute for Reproductive Health at Georgetown University in Washington, which conducts NFP research. Among married women worldwide who use a family planning method, approximately 14 percent use some form of periodic abstinence, according to the institute.
Efficacy, other concerns
The efficacy of NFP methods has been widely studied. Data collected during a World Health Organization (WHO) study in five countries -- New Zealand, India, Ireland, the Philippines and El Salvador -- showed that, when the cervical mucus approach to NFP (Billings Method) was used correctly, the first year probability of failure was 3.4 percent.5 Other analyses suggest the pregnancy rate during perfect use of the calendar method is 9 percent, but perfect use of the symptothermal method, in which multiple signs are used, results in only 2 percent failure. During typical use, however, the failure rates were greater -- 22.5 percent in the WHO study of the cervical mucus approach, for example.
This is similar to typical-use failure rates for barrier methods: spermicide use is 21 percent; for the diaphragm, 18 percent; for the male condom, 12 percent. Other modern methods, however, are more effective: a 3 percent failure rate during typical use for the pill and less than 1 percent failure for the Copper T IUD, the injectable depot-medroxyprogesterone acetate (DMPA), or the subdermal Norplant implant.6
Some types of NFP methods appear to be more effective than others. A study of 900 women in nine European countries, conducted by the University of Dusseldorf in Germany, found women using the symptothermal method to predict both the beginning and end of the fertile phase had lower rates of pregnancy than did women who used only one indicator to predict the beginning and end of the fertile phase (see article on NFP methods, at left). While unintended pregnancies were 5.6 percent for women younger than 25 and 3.2 percent for women ages 26 to 40, there were no unintended pregnancies for women over 40.7
While important, efficacy is not the only concern for a couple choosing a family planning method. Women and men consider other factors, such as side effects, the cost, and how the method fits into their lifestyle. "You cannot talk about efficacy in a vacuum," says Dr. Catherine D'Arcangues, WHO medical officer in Geneva. "It is part of the overall assessment of a method, which a woman makes in the context of her life circumstances."
Experts say clients should be informed about NFP as a family planning option, then be allowed to make their own decisions. Clients should consider several issues. Although NFP methods require monitoring of changes in the woman's body, to be effective the method requires the participation and cooperation of both partners. Health experts cite improvement in couple communication as a benefit of NFP use. However, for women who cannot control when they have sex or with whom, NFP is not a recommended alternative.
"If a woman has information on her fertility status but does not have the collaboration of her partner, natural family planning is not for her," says Dr. D'Arcangues of WHO. "Men need to be aware of their own fertility and reproductive health, and they need to understand women's fertility and reproductive health, so both can collaborate in using NFP, if they choose to do so."
NFP has no side effects and no medical contraindications, so women of any age can safely use these methods, as can women whose health problems preclude use of certain methods, such as oral contraceptives that contain estrogen. While some religions and cultures do not permit use of hormonal methods, barrier methods or IUDs, no religious prohibitions exist against NFP.
NFP can be difficult to use if a woman has irregular menstrual cycles; if infections or diseases are present that may alter cervical mucus or menstrual bleeding; or if she has recently given birth, is approaching menopause, or is an adolescent whose menstrual cycles have not yet become regular. Women with these circumstances need special counseling to learn how to use NFP effectively. Other health conditions can affect ovarian function and the regularity of the menstrual cycle, thus making NFP more difficult to use. These include a recent abortion, stroke, liver tumors or severe cirrhosis.
Other factors can also affect fertility symptoms. For example, lack of sleep, alcohol consumption and emotional stress can affect ovulation and body temperature. Some drugs can affect cervical mucus.
NFP offers no protection against sexually transmitted diseases (STDs), so couples at risk of HIV or other STDs should always use condoms. Although some couples believe normal cervical mucus inhibits transmission of STD microorganisms, this is not true.
Learning to use NFP
Once learned, NFP is a low-cost method because clients do not need to purchase contraceptive devices or drugs, or visit providers for supplies. However, it requires training, which can take as long as three months, and some clients may become pregnant while they are learning how to use NFP.
While family planning program managers and providers can easily include NFP when they counsel clients about the array of contraceptive choices available, training couples to use NFP requires staffing and other costs.
NFP can be taught by non-medical personnel. However, training takes time: providers may need to meet with clients more than once during the first month, and follow-up visits are needed to make sure couples are using the method correctly. NFP can be taught in groups, but individual meetings with clients are also recommended. For providers who are not trained in NFP or cannot integrate NFP instruction into their services, referrals to other programs that provide training may be an option.
A program in Bogotá, Colombia, found that one clinic's cost per couple year of protection (CYP) for NFP was U.S. $335, when the costs of an NFP instructor were included.8 Studies in Africa, however, found that CYP costs for NFP were approximately U.S. $26 in Zambia and U.S. $47 in Liberia.9
Among couples who use NFP, studies are currently under way to explore how couples use the method. WHO and the Institute for Reproductive Health are conducting research in Hungary, Sri Lanka, the Philippines and Peru on the calendar method, to understand how women who use this method define it and what steps they take to prevent pregnancy.
Researchers are concerned that many couples who say they use NFP are doing so incorrectly, says Dr. D'Arcangues of WHO. For example, WHO researchers found that in six countries -- Colombia, Indonesia, Sri Lanka, Ghana, Senegal and Brazil -- many women who said they were using NFP could not correctly identify the fertile phase of their menstrual cycle.
Incorrect knowledge of NFP methods was also reported in analysis of data from the Demographic and Health Surveys (DHS) in 12 countries. Among current NFP users in Liberia, only 29.3 percent could correctly identify the fertile phase of the menstrual cycle. In Thailand, the figure was 37.9 percent, and in the Dominican Republic, 49.2 percent.10 Educated women were more likely than uneducated women to know when the fertile phase occurs.
Even when couples have been trained in NFP techniques, periodic abstinence can be difficult to practice. An analysis of data collected during the five-country WHO study found that among 869 women using the cervical mucus method, 46 percent did not follow instructions to abstain from sex completely during the first month of NFP training.11
In exploring how couples use NFP, researchers are studying whether NFP can be used effectively in combination with other contraceptive methods. Studies have shown that many couples use NFP methods to identify the fertile phase of the menstrual cycle but use condoms or the withdrawal method instead of abstaining from intercourse.
A study of 1,300 European women using NFP found a large number of them used a barrier method or withdrawal during their fertile phase, and a 10-year study in Germany found that nearly half of the 300 women studied used barriers in conjunction with NFP.12 A study in the Philippines found that among 218 women who did not experience an unplanned pregnancy during NFP use, nearly 82 percent used withdrawal as a backup contraceptive, while nearly 17 percent used condoms.13
New approaches
In an attempt to improve NFP's efficacy and to make the method easier for couples to use, researchers are exploring new technologies and ways for identifying fertility signs.
In India, researchers have studied the Modified Mucus Method (MMM), called Prajanan Jagriti or "fertility awakening." In an attempt to improve acceptance among women who are illiterate or semi-literate and whose husbands are not highly motivated to use NFP, the approach uses training and support from village leaders and reduced periods of sexual abstinence. It does not require women to keep charts of changes in cervical mucus.
Thirty-seven female "leaders," supervised by 12 part-time coordinators, taught the method to 3,003 women in Uttar Pradesh and Madhya Pradesh. Over 10 months, there were 42 pregnancies among the women for a Pearl pregnancy rate of 2.04 percent per 100 woman-years.14
New technologies seek more precise ways to detect ovulation. In Germany, researchers developed Ladycomp and Cytotest, computerized thermometers to detect changes in basal body temperature. In Canada, researchers have tested Bioself, a hand-held electronic device that helps women to record combined NFP symptoms to predict ovulation.
In many industrialized nations, ovulation detection kits are used by women to measure the levels of luteinizing hormone and other hormones in their urine. These home kits typically are marketed to couples who are trying to conceive a child, rather than couples trying to prevent pregnancy.
One concern has been the question of whether NFP users have a higher rate of spontaneous abortions (miscarriages) and congenital malformations than non-users. Animal studies and some human studies have suggested that sperm or eggs that have remained in the male or female reproductive tract for a prolonged period and are at the end of their life span as gametes may be associated with a greater risk of spontaneous abortion.
Recent studies, however, have found no link between NFP use and a greater risk of miscarriage. In one study of women in the United States, Chile, Colombia and Italy among 868 pregnancies, 10.1 percent ended in miscarriage. The spontaneous abortion rate for optimally timed conceptions (those occurring on the day of ovulation) was 9.1 percent and 10.9 percent among non-optimally timed conceptions (those resulting from intercourse that occurred two or more days before ovulation and one or more days after ovulation).15
There also is no conclusive evidence to suggest that timing of conception influences the sex of the developing fetus.16
-- Barbara Barnett
References
- Hatcher RA, Trussell J, Stewart F, et al. Contraceptive Technology, Sixteenth Edition. (New York: Irvington Publishers Inc., 1994) 113.
- McDonald OP, Hardee K, Bailey W, et al. Quality of care among Jamaican private physicians offering family planning services. Adv Contracept 1995;11(3):245-54.
- Snowden R, Kennedy KI, Leon F, et al. Physicians' views of periodic abstinence methods: a study in four countries. Stud Fam Plann 1988;19(4):215-26.
- Perera HW, Steiner M, Kennedy KI, et al. Perspectives of physicians in Sri Lanka on periodic abstinence. Ceylon Medical Journal 1989;34(2):87-94.
- Trussell J, Grummer-Strawn L. Further analysis of contraceptive failure of the ovulation method. Am J Obstet Gynecol 1991;165(6)Part 2:2054-59.
- Hatcher.
- The European Natural Family Planning Study Groups. Prospective European multi-center study of natural family planning (1989-1992): Interim results. Adv Contracept 1993;9(4):269-83.
- Fundación Santa Fe de Bogotá and the Population Council. Provision of natural family planning methods through comprehensive health care systems. Operations Research Family Planning Database Project Summaries. New York: The Population Council, 1993.
- Gray RH, Kambic RT, Lanctot CA, et al. Evaluation of natural family planning programmes in Liberia and Zambia. J Biosoc Sci 1993;25(2):249-58.
- Sheon AR, Stanton C. Use of periodic abstinence and knowledge of the fertile period in 12 developing countries. Int Fam Plann Perspect 1989;15(1):29-34.
- Trussell.
- Gnoth C, Frank-Herrmann P, Freundl G, et al. Sexual behavior of natural family planning users in Germany and its changes over time. Adv Contracept 1995;11(2):173-85.
- Nolasco AD. Can natural family planning really work? Popul Forum 1989;1:13-16.
- Dorairaj K. The modified mucus method in India. Am J Obstet Gynecol 1991; 165(6) Part 2: 2066-67.
- Gray RH, Simpson JL, Kambic RT. Timing of conception and the risk of spontaneous abortion among pregnancies occurring during the use of natural family planning. Am J Obstet Gynecol 1995;172(5):1567-72.
- Gray RH. Natural family planning and sex selection: fact or fiction. Am J Obstet Gynecol 1991;165(6)Part 2:1982-84; Hatcher.
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