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Fertility Awareness (FA) is the practice of observing one or more of a woman’s primary fertility signs to determine the fertile and infertile phases of her cycle. Depending on their goals, couples may choose to time unprotected sexual intercourse so that it falls during the infertile phase (to avoid pregnancy) or the fertile phase (to achieve it). Using FA as a form of birth control is sometimes called the Fertility Awareness Method (FAM), although that term also refers to a specific method put forth in the bestselling book by Toni Weschler, Taking Charge of Your Fertility .

The term natural family planning can generally be used interchangably with fertility awareness, however Natural family planning can also more specifically refer to a set of natural birth control methods sanctioned by the Roman Catholic Church. In addition to promoting Fertility Awareness methods, NFP requires couples wishing to avoid pregnancy to abstain from sexual relations during the woman's fertile time.

Methods and Characteristics

There are several methods for practicing FA:

  • Basal Body Temperature (BBT), which relies on the phase shift of temperature during ovulation.
  • Cervical Fluid observation. (Cervical fluid is sometimes referred to as cervical mucus.) This includes the Billings Ovulation Method and the Creighton Model. An easier to teach, albeit less effective variation is the Two-Day Method.
  • Cervical Position is used as a confirmation of data obtained by observing other fertility signs, and not used by itself to predict fertility.
  • Sympto-thermo Method combines observations of BBT, cervical mucus, and sometimes cervical position.
  • Rhythm Method, Calendar Method or the Knaus-Ogino Method (named after Hermann Knaus and Kyusaku Ogino), relies solely on counting days in order to estimate the onset of a woman's fertile period. Because of its lower accuracy, however, many FA teachers consider calendar rhythm to have been obsolete for at least 20 years, and no longer teach it. Weschler, Toni, MPH, Taking Charge of Your Fertility 2002, pg.3-4
  • Women who are breastfeeding a child and wish to avoid pregnancy may be able to practice the Lactational Amenorrhea Method (LAM), or a stricter version known as Ecological Breastfeeding. These methods are not FA, but because they also do not involve devices or chemicals, they are often presented alongside FA as natural family planning.

Benefits

FA is unique in that it is the only family planning method that:

  • can have no possible side effects. (Some FA methods encourage internal observation of the cervix or cervical mucus - the insertion of fingers into the vagina for these observations might change the vaginal environment.)
  • can be free, depending on whether or not the couple chooses to use photocopied charts, a basal thermometer, special calendars, special computer software, or other paraphernalia.
  • uses no chemicals and may use no physical devices.
  • can be practiced in accord with moral beliefs of Catholics and adherents of various other religious sects.
  • can be used both to avoid pregnancy and to conceive a child.
  • can be used to track reproductive health in general, and aid in the diagnosis of gynecological health and/or fertility problems

FA can be used by all women throughout their reproductive life, regardless of whether or not a woman is having regular cycles, is approaching menopause, or is breastfeeding.

Avoiding pregnancy with FA

Like the Pill and other non-barrier contraceptives, FA offers no protection against sexually transmitted diseases. FA methods do require regular, consistent effort to determine when a couple's chance of fertility is low. For many women, the times of high fertility coincide with the time of highest libido. The "scheduling" of sex required can be inconvenient for partners who do not live together and are unwilling to abstain or use non-procreative forms of sex when they are able to spend time together. For these reasons, other methods are more popular than FA among large sections of society.

FA can be combined with other forms of birth control, such as condoms. Many couples will use a "back-up" method during the fertile phase, instead of abstaining from intercourse. Couples seeking maximum effectiveness might use their "back-up" method during the infertile phase, and abstain from intercourse during the fertile phase.

Avoiding pregnancy by use of FA requires abstinance from sexual intercourse for at least 8-10 days each cycle. Achieving the highest effectiveness rates can require even more abstinence, though it is rare for couples to need to abstain for more than two weeks. Despite these periods of required abstinence, studies have indicated little or no difference in frequency of intercourse between couples using fertility awareness and those using oral contraceptives. (Couples avoiding intercourse during the fertile phase of the cycles are thus more sexually active during the infertile phases of the cycle.)

Birth Control Effectiveness in General

The effectiveness of FA, as of artificial forms of contraception, can be assessed two ways: method effectiveness and actual effectiveness. The method effectiveness is the proportion of couples correctly and consistently using the method who do not become pregnant. Actual effectiveness is the proportion of couples who intended that method as their sole form of birth control and do not become pregnant; it includes couples who sometimes use the method incorrectly, or sometimes not at all. Effectiveness rates are generally presented per one year of use.

For all forms of contraception, actual effectiveness is lower than method effectiveness, due to several factors:

  • mistakes on the part of those providing instructions on how to use the method
  • mistakes on the part of the method's users
  • conscious user non-compliance with method.
For instance, someone using oral forms of hormonal birth control might be given incorrect information by a health care provider as to the frequency of intake, or by mistake not take the pill one day, or simply not bother to go to the pharmacy on time to renew the prescription.

Effectiveness of Fertility Awareness

The highest effectiveness rates of FA (when used to avoid pregnancy) are found in couples that received instruction from an experienced teacher. Many couples learn FA from one of the comprehensive books on the subject, often in conjunction with online support forums, but this is thought to result in higher actual failure rates. If the intent is to avoid pregnancy, learning solely from passive online material is not recommended.

When used correctly and consistently, studies have shown some forms of FA to be 99% effective, the same as oral contraceptives.Ecochard, R.; Pinguet, F.; Ecochard, I.; De Gouvello, R.; Guy, M.; and Huy, F. (1998) "Analysis of natural family planning failures. In 7007 cycles of use", Fertilite Contraception Sexualite 26(4):291-6Hilgers T.W. and Stanford J.B. (1998) "Creighton Model NaProEducation Technology for avoiding pregnancy. Use effectiveness", Journal of Reproductive Medicine 43(6):495-502Evaluation of the Effectiveness of a Natural Fertility Regulation Programme in China: Shao-Zhen Qian, et al. Reproduction and Contraception (English edition), in press 2000.Howard, M.P. and Stanford, J.B. (1999) "Pregnancy probabilities during use of the Creighton Model Fertility Care System", Archives of Family Medicine 8(5):391-402

From Contraceptive Technology James Trussell et al. (2000) "Contraceptive effectiveness rates", Contraceptive Technology — 18th Edition, New York: Ardent Media. On-press.:

  • Post-ovulation methods (i.e. abstaining from intercourse from menstruation until after ovulation) have a method failure rate of 1% per year.
  • The symptothermo method has a method failure rate of 2% per year.
  • The cervical mucus-only methods have a method failure rate of 3% per year.
  • Calendar rhythm has a method failure rate of 9% per year.
  • The Standard Days Method has a method failure rate of 5% per year.

For all fertility awareness methods, actual effectiveness can be significantly lower than method effectiveness - some studies have found actual failure rates of 25% per year or higher. Actual failure rates vary widely depending on the population being studied and the teaching method - at least one study has found an actual failure rate of less than 1% per year, and several studies have found actual failure rates of 2-3% per year.

The most common reason for the lower actual effectiveness is not mistakes on the part of instructors or users, but conscious user non-compliance, i.e., the couple knowing that the woman is likely to be fertile at the time, but engaging in sexual intercourse nonetheless. This is similar to failures of barrier methods, which are primarily caused by non-use of the method.

Achieving pregnancy with FA

A study by Barrett and Marshall has shown that random acts of intercourse achieve a 24% pregnancy rate per cycle. That study also found that timed intercourse based on information from a BBT-only method of FA increased pregnancy rates to 31%-68%.

Studies of cervical-mucus methods of fertility awareness have found pregnancy rates of 67%-81% per cycle if intercourse occurred on the Peak Day of the mucus sign.Ryder, R.E. "Natural family planning": effective birth control supported by the Catholic Church. BMJ. 1993 Sep 18;307(6906):723-6. PMID 8401097Hilgers, T.W. et. al. Cumulative pregnancy rates in patients with apparently normal fertility and fertility-focused intercourse. Journal of Reproductive Medicine. 1992 Oct;37(10):864-6. PMID 1479570

Scientific Basis

Ova die if not fertilized within 24 hours of ovulation. Ovulation can be detected through changes in basal body temperatures, cervical mucus, and/or cervical position. Once ovulation has passed, conception is not possible for the remainder of the menstrual cycle. Spermatozoa are able to fertilize an ovum for a period of up to five days after they have been ejaculated. If no fertile cervical mucus is present, the acidic environment of the vagina usually results in a dramatically shorter sperm life. Intercourse that occurs more than five days before ovulation will not result in pregnancy. Intercourse that occurs in the presence of cervical mucus, and/or right before the temperature shift is most likely to result in pregnancy. Most women experience fertile cervical mucus and cervical position changes five or more days before ovulation occurs, giving them sufficient notice to avoid or plan intercourse (depending on their pregnancy intentions).

Observational Methods

This description is an overview only. Couples wishing to use Fertility Awareness to avoid or encourage pregnancy should seek instruction from an experienced teacher.

The three primary fertility signs are basal body temperature (BBT), cervical mucus, and cervical position. A woman practicing fertility awareness may choose to observe one sign, two signs, or, all three.

Basal body temperature is a person’s temperature taken when they first wake up in the morning (or after their longest sleep period of the day). In women, ovulation will trigger a rise in BBT between 0.3 and 0.9C (0.5 and 1.6°F) that lasts approximately until the next menstruation. Sixty percent of the time, ovulation happens the day before the temperature rise. The other forty percent of the time, ovulation may happen a few days in either direction.

The appearance of cervical mucus and vulvar sensation are generally described together as two ways of observing the same sign. Cervical mucus is produced by the cervix, the muscle that separates the uterus from the vaginal canal. Cervical mucus is a heterogeneous mixture of different types of mucus, several of which have specialized functions. Some of its functions are similar to those of semen - cervical mucus promotes sperm life by decreasing the acidity of the vagina and providing nourishment to the sperm. One type of mucus has a structure that helps guide sperm into the cervix and then the uterus. The production of fertile cervical mucus is caused by the same hormone (estrogen) that prepares a woman’s body for ovulation. By observing her cervical mucus, and paying attention to the sensation as it passes the vulva, a woman can detect when her body is gearing up for ovulation, and also when ovulation has passed. When ovulation occurs, estrogen production drops slightly and progesterone starts to rise. The rise in progesterone causes a distinct change in the quantity and quality of mucus observed at the vulvaOvarian Activity and Fertility . Each of the methods of fertility awareness observes and interprets this occurrence differently, and uses different rules to determine the onset of fertility and post-ovulatory infertility.

The cervix changes position in response to the same hormones that cause cervical mucus to be produced and to dry up. When a woman is in an infertile phase of her cycle, the cervix will be low in the vaginal canal; it will feel firm to the touch (like the tip of a person’s nose); and, the os – the opening in the cervix – will be relatively small, or ‘closed’. As a woman becomes more fertile, the cervix will rise higher in the vaginal canal; it will become softer to the touch (more like a person’s lips); and the os will become more open. After ovulation has occurred, the cervix will revert to its infertile position.

There are other techniques for detecting ovulation. Unlike the three primary signs described above, these other methods are not considered sufficiently accurate to avoid pregnancy. They are often used by couples seeking to conceive.

Ovulation Predictor Kits (OPKs) can detect imminent ovulation from the concentration of lutenizing hormone (LH) in a woman’s urine. A positive OPK is usually followed by ovulation within 12-36 hours.

Saliva microscopes, when correctly used, can detect ferning structures in the saliva that precede ovulation. Ferning is usually detected beginning three days before ovulation, and continuing until ovulation has occurred.

Fertility monitors are available under various brand names. These monitors use a combination of the calendar method, OPKs, and sometimes computerized interpretation of BBTs. Though the manufacturers claim high effectiveness rates for avoiding pregnancy, independent studies show failure rates comparable to the calendar method.

Many women experience secondary fertility signs that correlate loosely with ovulation. Examples include breast tenderness and mittleschmerz (ovulation pains).

Books

Garden of Fertility by Katie Singer.

Taking Charge of Your Fertility by Toni Weschler.

The Art of Natural Family Planning by John and Sheila Kippley.

External links

Teaching organizations

Secular

Catholic

FA/NFP descriptions

Secular sources

Religious sources
Not all sources have religious content on their webpage

Software

References

Periodic abstinence

Symptothermale Methode | Planification familiale naturelle | Metodo sintotermico | Riconoscimento della fertilità | Simptoterminis metodas | Periodieke onthouding

 

This article is licensed under the GNU Free Documentation License. It uses material from the "Fertility awareness".

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