View source for Fertility awareness

{{Short description|Methods to determine menstrual phases}}
{{Infobox Birth control
|name                 = Fertility awareness
|image                = Pregnancy chance by day near ovulation.jpg
|width                =
|caption              = Chance of [[human fertilization|fertilization]] by day relative to [[ovulation]].<ref name="DunsonBaird1999">{{cite journal|last1=Dunson|first1=D.B.|last2=Baird|first2=D.D.|last3=Wilcox|first3=A.J.|last4=Weinberg|first4=C.R.|author4-link=Clarice Weinberg|title=Day-specific probabilities of clinical pregnancy based on two studies with imperfect measures of ovulation|journal=Human Reproduction|volume=14|issue=7|year=1999|pages=1835–1839|issn=1460-2350|doi=10.1093/humrep/14.7.1835|pmid=10402400|doi-access=free}}</ref>
|bc_type              = Behavioral
|date_first_use       = 1950s (mucus) <br />mid-1930s (BBT) <br />1930 (Knaus-Ogino) <br />Ancient (ad hoc)
|rate_type            = Failure
|perfect_failure% = Symptothermal method: 0.4%<ref name="Trussell 2011">{{cite book|last=Trussell|first=James|year=2011|chapter=Contraceptive efficacy|editor1-last=Hatcher|editor1-first=Robert A.|editor2-last=Trussell|editor2-first=James|editor3-last=Nelson|editor3-first=Anita L.|editor4-last=Cates|editor4-first=Willard Jr.|editor5-last= Kowal|editor5-first=Deborah|editor6-last=Policar|editor6-first=Michael S.|title=Contraceptive technology|edition=20th revised|location=New York|publisher=Ardent Media|isbn=978-1-59708-004-0|issn = 0091-9721|oclc=781956734|pages=779–863}} Table 26–1 = <span class="plainlinks">[http://www.contraceptivetechnology.org/wp-content/uploads/2013/09/CTFailureTable.pdf Table 3–2 Percentage of women experiencing an unintended pregnancy during the first year of typical use and the first year of perfect use of contraception, and the percentage continuing use at the end of the first year. United States.] {{Webarchive|url=https://web.archive.org/web/20170215224018/http://www.contraceptivetechnology.org/wp-content/uploads/2013/09/CTFailureTable.pdf |date=2017-02-15 }}</span></ref><br />Ovulation method: 3%<ref name="Trussell 2011"/><br />TwoDay method: 4%<ref name="Trussell 2011"/><br />Standard Days method: 5
|perfect_failure_ref =<ref name="Trussell 2011"/>
|typical_failure% = Symptothermal method: 2% <br /> Ovulation Method: 11–34% <br /> TwoDay Method: 14% <br /> Standard Days Method: 11–14% <br /> Calendar Rhythm Method: 24
|typical_failure_ref =<ref name="Urrutia, Rachel Peragallo; Polis, Chelsea B. (2019-07-11)" />
|duration_effect      =
|reversibility        = Yes
|user_reminders       = Dependent upon strict user adherence to methodology
|clinic_interval      = None
|STD_protection_YesNo = No
|periods              = Increased prediction
|benefits             = No side effects, can aid pregnancy achievement, personal self-awareness, greater marital intimacy
|weight_gain_loss     =
|risks                =
|medical_notes        =
}}'''Fertility awareness''' ('''FA''') refers to a set of practices used to determine the [[fertility|fertile]] and infertile phases of a woman's [[menstrual cycle]]. Fertility awareness methods may be used to [[birth control|avoid pregnancy]], to [[fertilisation|achieve pregnancy]], or as a way to monitor [[female reproductive system (human)|gynecological]] health.

Methods of identifying infertile days have been known since antiquity, but scientific knowledge gained during the past century has increased the number, variety, and especially accuracy of methods.

Systems of fertility awareness rely on observation of changes in one or more of the primary fertility signs ([[basal body temperature]], [[cervical mucus]], and cervical position), tracking menstrual cycle length and identifying the fertile window based on this information, or both. Other signs may also be observed: these include [[Mastodynia|breast tenderness]] and [[mittelschmerz]] (ovulation pains), urine analysis strips known as ovulation predictor kits (OPKs), and microscopic examination of saliva or cervical fluid. Also available are computerized [[fertility monitor]]s.

==Terminology==
Symptoms-based methods involve tracking one or more of the three primary fertility signs: [[basal body temperature]], [[cervical mucus]], and cervical position.<ref name="tcoyf">{{cite book | first=Toni | last=Weschler | year=2002 | title=Taking Charge of Your Fertility | url=https://archive.org/details/takingchargeofyo00toni | url-access=registration | pages=[https://archive.org/details/takingchargeofyo00toni/page/52 52] | edition=Revised | publisher=HarperCollins | location=New York | isbn=0-06-093764-5 }}</ref> Systems relying exclusively on cervical mucus include the [[Billings Ovulation Method]], the [[Creighton Model]], and the Two-Day Method. Symptothermal methods combine observations of basal body temperature (BBT), cervical mucus, and sometimes cervical position. [[Calendar-based methods]] rely on tracking a woman's cycle and identifying her fertile window based on the lengths of her cycles. The best known of these methods is the [[Standard Days Method]]. The Calendar-Rhythm method is also considered a calendar-based method, though it is not well defined and has many different meanings to different people.

Systems of fertility awareness may be referred to as fertility awareness–based methods;<ref name="who">{{Cite book |title=Medical Eligibility Criteria for Contraceptive Use:Fertility awareness-based methods |version=Fourth edition |publisher=World Health Organization |year=2010 |url=https://www.who.int/reproductivehealth/publications/family_planning/9789241563888/en/index.html |access-date=2012-12-11 |archive-url=https://web.archive.org/web/20121102140038/http://www.who.int/reproductivehealth/publications/family_planning/9789241563888/en/index.html |archive-date=2012-11-02 |isbn=978-9-2415-6388-8}}</ref> the term Fertility Awareness Method (FAM) refers specifically to the system taught by Toni Weschler. The term [[natural family planning]] is sometimes used to refer to any use of fertility awareness methods, the [[lactational amenorrhea]] method and periodic [[abstinence]] during fertile times. A method of fertility awareness may be used by natural family planning users to identify these fertile times.

Women who are breastfeeding a child and wish to avoid pregnancy may be able to practice the lactational amenorrhea method. The lactational amenorrhea method is distinct from fertility awareness, but because it also does not involve contraceptives, it is often presented alongside fertility awareness{{By whom|date=September 2011}} as a method of "natural" birth control.

Within the [[Catholic Church]] and some [[Protestant]] denominations, the term natural family planning is often used to refer to Fertility Awareness pointing out it is the only method of [[family planning]] approved by the Church.<ref>{{cite book|last=O'Reilly|first=Andrea|title=Encyclopedia of Motherhood|url=https://archive.org/details/encyclopediamoth00orei|url-access=limited|date=6 April 2010|publisher=SAGE Publications|language=en|isbn=978-1-4522-6629-9|page=[https://archive.org/details/encyclopediamoth00orei/page/n1105 1056]|quote=The Roman Catholic church and some Protestant denominations have approved only "natural family planning" methods--including the rhythm method and periodic abstinence.}}</ref><ref>{{cite book|last=Green|first=Joel B.|title=Dictionary of Scripture and Ethics|date=1 November 2011|publisher=Baker Books|language=en|isbn=978-1-4412-3998-3|page=303|quote=In 1968, Paul VI reiterated the traditional Catholic prohibition against all but "natural family planning" (abstinence during fertile periods), which many Catholics and some Protestants continue to practice.}}</ref>

==History==

===Development of calendar-based methods===
{{Main|Calendar-based methods#History}}
It is not known exactly when it was first discovered that women have predictable periods of fertility and infertility. It is already clearly stated in the Talmud tractate Niddah, that a woman only becomes pregnant in specific periods in the month, which seemingly refers to ovulation. [[Augustine of Hippo|St. Augustine]] wrote about periodic abstinence to avoid pregnancy in the year 388 (the [[Manichaeans]] attempted to use this method to remain [[childfree]], and Augustine condemned their use of periodic abstinence).<ref name="augustine">{{cite book |last=Saint |first=Bishop of Hippo Augustine |editor=Philip Schaff |title=A Select Library of the Nicene and Post-Nicene Fathers of the Christian Church, Volume IV |publisher=WM. B. Eerdmans Publishing Co. |year=1887 |location=Grand Rapids, MI |chapter-url=http://www.ccel.org/ccel/schaff/npnf104.iv.v.xx.html |chapter=Chapter 18.—Of the Symbol of the Breast, and of the Shameful Mysteries of the Manichæans}}</ref> One book states that periodic abstinence was recommended ''"by a few secular thinkers since the mid-nineteenth century,"''<ref name="wife">{{cite book | first=Marilyn | last=Yalom | year=2001 | title=A History of the Wife | edition=First | publisher=HarperCollins | location=New York | isbn=0-06-019338-7 | pages=[https://archive.org/details/historyofwife00mari/page/297 297]–8, 307 | url=https://archive.org/details/historyofwife00mari | url-access=registration }}</ref> but the dominant force in the twentieth century popularization of fertility awareness-based methods was the [[Catholic Church|Roman Catholic Church]].

In 1905 [[Theodoor Hendrik van de Velde]], a Dutch gynecologist showed that women only ovulate once per menstrual cycle.<ref>{{cite web | title=A Brief History of Fertility Charting | work=FertilityFriend.com | url=http://www.fertilityfriend.com/Faqs/A_brief_history_of_fertility_charting.html | access-date=2006-06-18}}</ref>  In the 1920s, [[Kyusaku Ogino]], a Japanese gynecologist, and Hermann Knaus, from Austria, independently discovered that ovulation occurs about fourteen days before the next menstrual period.<ref name="singer">{{cite book | first=Katie | last=Singer | year=2004 | title=The Garden of Fertility | publisher=Avery, a member of Penguin Group (USA) | location=New York | isbn=1-58333-182-4 |pages=226–7}}</ref>  Ogino used his discovery to develop a formula for use in aiding infertile women to time intercourse to achieve pregnancy.<!-- This is from the Japanese article on Ogino (as best I could tell from the internet translator I used), but that page does not cite its sources --> In 1930, John Smulders, a Roman Catholic physician from the Netherlands, used this discovery to create a method for ''avoiding'' pregnancy. Smulders published his work with the Dutch Roman Catholic medical association, and this was the first formalized system for periodic abstinence: the [[Calendar-based methods|rhythm method]].<ref name="singer" />

===Introduction of temperature and cervical mucus signs===
In the 1930s, Reverend Wilhelm Hillebrand, a Catholic priest in Germany, developed a system for avoiding pregnancy based on basal body temperature.<ref name="puzzle">{{cite journal |last=Hays |first=Charlotte |title=Solving the Puzzle of Natural Family Planning |journal=Holy Spirit Interactive |url=http://www.holyspiritinteractive.net/features/prolife/article_05.asp |access-date=2012-02-15 |archive-url=https://web.archive.org/web/20120226002800/http://www.holyspiritinteractive.net/features/prolife/article_05.asp |archive-date=2012-02-26 }}</ref> This temperature method was found to be more effective at helping women avoid pregnancy than were [[calendar-based methods]]. Over the next few decades, both systems became widely used among Catholic women. Two speeches delivered by [[Pope Pius XII]] in 1951 gave the highest form of recognition to the Catholic Church's approval—for couples who needed to avoid pregnancy—of these systems.<ref name="wife" /><ref>''Moral Questions Affecting Married Life'': Addresses given [http://www.ewtn.com/library/PAPALDOC/P511029.HTM October 29, 1951 to the Italian Catholic Union of midwives] {{Webarchive|url=https://web.archive.org/web/20101206084012/http://www.ewtn.com/library/PAPALDOC/P511029.HTM |date=December 6, 2010 }} and November 26, 1951, to the National Congress of the Family Front and the Association of Large Families, National Catholic Welfare Conference, Washington, DC.</ref>  In the early 1950s, [[John Billings (Australian physician)|John Billings]] discovered the relationship between cervical mucus and fertility while working for the Melbourne Catholic Family Welfare Bureau. Billings and several other physicians, including his wife, Dr. Evelyn Billings, studied this sign for a number of years, and by the late 1960s had performed clinical trials and begun to set up teaching centers around the world.<ref>{{cite journal |last=Billings |first=John |author-link=John Billings (Australian physician) |title=THE QUEST&nbsp;— leading to the discovery of the Billings Ovulation Method |journal=Bulletin of Ovulation Method Research and Reference Centre of Australia |volume=29 |issue=1 |pages=18–28 |date=March 2002 |url=http://www.woomb.org/omrrca/bulletin/vol29/no1/thequest.shtml |access-date=2007-03-18 |archive-url=https://web.archive.org/web/20070219081722/http://www.woomb.org/omrrca/bulletin/vol29/no1/thequest.shtml |archive-date=2007-02-19 }}</ref>

===First symptoms-based teaching organizations===
While Dr. Billings initially taught both the temperature and mucus signs, they encountered problems in teaching the temperature sign to largely illiterate populations in developing countries. In the 1970s they modified the method to rely on only mucus.<ref name="puzzle" />  The international organization founded by Dr. Billings is now known as the World Organization Ovulation Method Billings.

The first organization to teach a symptothermal method was founded in 1971. John and Sheila Kippley, lay Catholics, joined with Dr. Konald Prem in teaching an observational method that relied on all three signs: temperature, mucus, and cervical position. Their organization is now called Couple to Couple League International.<ref name="puzzle" /> The next decade saw the founding of other now-large Catholic organizations, Family of the Americas (1977), teaching the Billings method,<ref>{{cite web |title=About us |work=Family of the Americas |year=2006 |url=http://www.familyplanning.net/main.php?parent_id=1&id_area=1 |access-date=2007-03-18 |archive-url=https://web.archive.org/web/20070213070450/http://www.familyplanning.net/main.php?parent_id=1&id_area=1 |archive-date=2007-02-13 }}</ref> and the Pope Paul VI Institute (1985), teaching a new mucus-only system called the Creighton Model.<ref>{{cite web |title=About the Institute |work=Pope Paul VI Institute |year=2006 |url=http://www.popepaulvi.com/about2.html |access-date=2012-02-21 |archive-date=2012-03-12 |archive-url=https://web.archive.org/web/20120312012943/http://www.popepaulvi.com/about2.html }}</ref>

Up until the 1980s, information about fertility awareness was only available from Catholic sources.<ref>Singer (2004), p.xxiii</ref> The first secular teaching organization was the Fertility Awareness Center in New York, founded in 1981.<ref>{{cite web |title=About us |work=Fertility Awareness Center |year=2006 |url=http://www.fertaware.com/ |access-date=2007-03-18 }}</ref> Toni Weschler started teaching in 1982 and published the bestselling book ''Taking Charge of Your Fertility'' in 1995.<ref>Weschler (2002)</ref> Justisse was founded in 1987 in Edmonton, Canada.<ref>Justisse Healthworks for Women. (2015). [http://justisse.ca/index.php/pages/page/about-justisse "About Us"] {{Webarchive|url=https://web.archive.org/web/20210808190940/https://justisse.ca/index.php/pages/page/about-justisse |date=2021-08-08 }}.</ref> These secular organizations all teach symptothermal methods. Although the Catholic organizations are significantly larger than the secular fertility awareness movement, independent secular teachers have become increasingly common since the 1990s.

===Ongoing development===
Development of fertility awareness methods is ongoing. In the late 1990s, the Institute for Reproductive Health at [[Georgetown University]] introduced two new methods.<ref>{{cite journal |vauthors=Arévalo M, Jennings V, Sinai I |title=Efficacy of a new method of family planning: the Standard Days Method. | journal = Contraception | volume = 65 | issue = 5 |pages=333–8 |year=2002 | pmid = 12057784 | doi = 10.1016/S0010-7824(02)00288-3}}</ref><ref>{{cite journal |vauthors=Jennings V, Sinai I |title=Further analysis of the theoretical effectiveness of the TwoDay method of family planning |journal=Contraception |volume=64 |issue=3 |pages=149–53 |year=2001 |pmid=11704093 | doi = 10.1016/S0010-7824(01)00251-7}}</ref> The TwoDay Method, a mucus-only system, and [[CycleBeads]] and iCycleBeads (the digital version), based on the Standard Days Method, are designed to be both effective and simple to teach, learn, and use. In 2019, Urrutia et al. released a study as well as interactive graph over-viewing all studied fertility awareness based methods.<ref name="Urrutia, Rachel Peragallo; Polis, Chelsea B. (2019-07-11)">{{Cite journal|last1=Urrutia|first1=Rachel Peragallo|last2=Polis|first2=Chelsea B.|date=2019-07-11|title=Fertility awareness based methods for pregnancy prevention|url=https://www.bmj.com/content/366/bmj.l4245|journal=BMJ|language=en|volume=366|article-number=l4245|doi=10.1136/bmj.l4245|issn=0959-8138|pmid=31296535|s2cid=195893695|url-access=subscription}}</ref> [[Femtech]] companies such as Dot<ref>{{Cite journal|last1=Jennings|first1=Victoria H.|last2=Haile|first2=Liya T.|last3=Simmons|first3=Rebecca G.|last4=Fultz|first4=Hanley M.|last5=Shattuck|first5=Dominick|date=2019-01-01|title=Estimating six-cycle efficacy of the Dot app for pregnancy prevention|url=https://www.contraceptionjournal.org/article/S0010-7824(18)30457-8/abstract|journal=Contraception|language=en|volume=99|issue=1|pages=52–55|doi=10.1016/j.contraception.2018.10.002|issn=0010-7824|pmid=30316782|doi-access=free}}</ref> and [[Natural Cycles]] have also produced new studies and apps to help women avoid pregnancy. [[Natural Cycles]] is the first app of its kind to receive FDA approval.<ref>{{Cite web|url=https://www.fda.gov/news-events/press-announcements/fda-allows-marketing-first-direct-consumer-app-contraceptive-use-prevent-pregnancy|archive-url=https://web.archive.org/web/20190427223321/https://www.fda.gov/news-events/press-announcements/fda-allows-marketing-first-direct-consumer-app-contraceptive-use-prevent-pregnancy|archive-date=April 27, 2019|title=FDA allows marketing of first direct-to-consumer app for contraceptive use to prevent pregnancy|last=Health|first=Center for Devices and Radiological|date=2019-09-11|website=FDA|language=en|access-date=2019-10-01}}</ref>

==Fertility signs==
Most menstrual cycles have several days at the beginning that are infertile (pre-ovulatory infertility), a period of fertility, and then several days just before the next menstruation that are infertile (post-ovulatory infertility). The first day of red bleeding is considered day one of the menstrual cycle. Different systems of fertility awareness calculate the fertile period in slightly different ways, using primary fertility signs, cycle history, or both.

==Primary fertility signs==
The three '''primary signs''' of fertility are ''[[basal body temperature]]'' (BBT), ''cervical mucus'', and ''cervical position''. A woman practicing symptoms-based fertility awareness may choose to observe one sign, two signs, or all three. Many women experience '''secondary fertility signs''' that correlate with certain phases of the menstrual cycle, such as [[abdominal pain]] and heaviness, [[back pain]], [[Mastodynia|breast tenderness]], and [[mittelschmerz]] (ovulation pains).

===Basal body temperature===
This usually refers to a temperature reading collected when a person first wakes up in the morning (or after their longest sleep period of the day). The true BBT can only be obtained by continuous temperature monitoring through internally worn temperature sensors. In women, [[ovulation]] will trigger a rise in BBT between 0.2º and 0.5&nbsp;°C. (0.5 and 1.°F) that lasts approximately until the next menstruation. This temperature shift may be used to determine the onset of post-ovulatory infertility. (See ref. 30)

===Cervical mucus===
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, which connects the uterus to the vaginal canal. Fertile cervical mucus promotes sperm life by decreasing the acidity of the vagina, and also it helps guide sperm through the cervix and into the uterus. The production of fertile cervical mucus is caused by estrogen, the same hormone 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 vulva.<ref>{{cite web | author=James B. Brown | title=Physiology of Ovulation | year=2005 | work=Ovarian Activity and Fertility and the Billings Ovulation Method | url=http://www.woomb.org/bom/science/physiology.html | publisher=Ovulation Method Research and Reference Centre of Australia | archive-url=https://web.archive.org/web/20051224031839/http://www.woomb.org/bom/science/physiology.html | archive-date=2005-12-24 }}</ref>

===Cervical position===
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.

==Cycle history==
Calendar-based systems determine both pre-ovulatory and post-ovulatory infertility based on cycle history. When used to avoid pregnancy, these systems have higher perfect-use failure rates than symptoms-based systems but are still comparable with barrier methods, such as [[diaphragm (contraceptive)|diaphragms]] and [[cervical cap]]s.

Mucus- and temperature-based methods used to determine post-ovulatory infertility, when used to avoid conception, result in very low perfect-use pregnancy rates.<ref>Kippley (2003), pp.121-134,376-381</ref> However, mucus and temperature systems have certain limitations in determining pre-ovulatory infertility. A temperature record alone provides no guide to fertility or infertility before ovulation occurs. Determination of pre-ovulatory infertility may be done by observing the absence of fertile cervical mucus; however, this results in a higher failure rate than that seen in the period of post-ovulatory infertility.<ref>Kippley (2003), p.114</ref> Relying only on mucus observation also means that unprotected sexual intercourse is not allowed during [[menstruation]], since any mucus would be obscured.<ref>{{cite book |author=Evelyn Billings |author2=Ann Westinore |title=The Billings Method: Controlling Fertility Without Drugs or Devices |publisher=Life Cycle Books |location=Toronto |year=1998 |page=47 |isbn=0-919225-17-9}}</ref>

The use of certain calendar rules to determine the length of the pre-ovulatory infertile phase allows unprotected intercourse during the first few days of the menstrual cycle while maintaining a very low risk of pregnancy.<ref name="calendar">Kippley (2003), pp.108-113</ref> With mucus-only methods, there is a possibility of incorrectly identifying mid-cycle or anovulatory bleeding as menstruation. Keeping a basal body temperature chart enables accurate identification of menstruation, when pre-ovulatory calendar rules may be reliably applied.<ref>Kippley (2003), p.101 sidebar and Weschler (2002), p.125</ref> In temperature-only systems, a calendar rule may be relied on alone to determine pre-ovulatory infertility. In symptothermal systems, the calendar rule is cross-checked by mucus records: observation of fertile cervical mucus overrides any calendar-determined infertility.<ref name="calendar" />

Calendar rules may set a standard number of days, specifying that (depending on a woman's past cycle lengths) the first three to six days of each menstrual cycle are considered infertile.<ref>Kippley (2003), pp.108-109 and Weschler (2002), pp.125-126</ref> Or, a calendar rule may require calculation, for example holding that the length of the pre-ovulatory infertile phase is equal to the length of a woman's shortest cycle minus 21 days.<ref>Kippley (2003), pp.110-111</ref> Rather than being tied to cycle length, a calendar rule may be determined from the cycle day on which a woman observes a thermal shift. One system has the length of the pre-ovulatory infertile phase equal to a woman's earliest historical day of temperature rise minus seven days.<ref>Kippley (2003), pp.112-113</ref>

==Other techniques==
Ovulation predictor kits can detect imminent ovulation from the concentration of [[luteinizing hormone]] (LH) in a woman's urine. A positive ovulation predictor kit result 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. During this window, ferning structures occur in cervical mucus as well as saliva.

Computerized fertility monitors, such as Lady-Comp, are available under various brand names. These monitors may use BBT-only systems, they may analyze urine test strips, they may use symptothermal observations, they may monitor the electrical resistance of saliva and vaginal fluids, or a combination of any of these factors.

A symptohormonal method of fertility awareness method developed at Marquette University uses the ClearBlue Easy fertility monitor to determine the fertile window.<ref>{{Cite web |url=https://www.marquette.edu/nursing/natural-family-planning-model.php |title=Institute for Natural Family Planning Model - Marquette University |access-date=2022-10-11 |website=www.marquette.edu}}</ref> The monitor measures estrogen and LH to determine the peak day. This method is also applicable during postpartum, breastfeeding, and perimenopause, and requires less abstinence than other fertility awareness method methods.<ref>{{Cite journal |title=Comparison of Abstinence and Coital Frequency Between 2 Natural Methods of Family Planning |journal=Journal of Midwifery & Women's Health |url=https://epublications.marquette.edu/cgi/viewcontent.cgi?article=1343&context=nursing_fac |last1=Fehring |first1=Richard J. |date=2014-09-01 |issue=5 |volume=59 |pages=528–532 |last2=Schneider |first2=Mary |doi=10.1111/jmwh.12216}}</ref> Some couples prefer this method because the monitor reading is objective and is not affected by sleep quality as basal body temperature can be.

==Benefits and drawbacks==
Fertility awareness has a number of unique characteristics:

* Fertility awareness can be used to monitor reproductive health. Changes in the cycle can alert the user to emerging gynecological problems. Fertility awareness can also be used to aid in diagnosing known gynecological problems such as infertility.
* Fertility awareness may be used to avoid pregnancy or to aid in conception.
* Use of fertility awareness can give insight to the workings of women's bodies, and may allow women to take greater control of their own fertility.
* Some symptoms-based forms of fertility awareness require observation or touching of cervical mucus, an activity with which some women are not comfortable. Some practitioners prefer to use the term "cervical fluid" to refer to cervical mucus, in an attempt to make the subject more acceptable to these women.
* Some drugs, such as decongestants, can change cervical mucus. In women taking these drugs, the mucus sign may not accurately indicate fertility.<ref name="ffh">{{cite web | year =2004 | url =http://www.fertilityfriend.com/HelpCenter/FFBook/ff_fertility_signs.html | title =How to Observe and Record Your Fertility Signs | work =Fertility Friend Handbook | publisher =Tamtris Web Services | access-date =2005-06-15 | archive-date =2005-05-28 | archive-url =https://web.archive.org/web/20050528235842/http://www.fertilityfriend.com/HelpCenter/FFBook/ff_fertility_signs.html }}</ref>
* Some symptoms-based methods require tracking of basal body temperatures. Because irregular sleep can interfere with the accuracy of basal body temperatures, shift workers and those with very young children, for example, might not be able to use those methods.<ref name="ffh" />
* FA requires action daily—detailed record keeping. Some may find the time and detail requirements too complicated.

==As birth control==
By restricting unprotected sexual intercourse to the infertile portion of the menstrual cycle, a woman and her partner can prevent pregnancy. During the fertile portion of the menstrual cycle, the couple may use [[barrier contraception]] or abstain from sexual intercourse.<ref name="FABM">{{cite journal|last1=Manhart|first1=MD|last2=Daune|first2=M|last3=Lind|first3=A|last4=Sinai|first4=I|last5=Golden-Tevald|first5=J|title=Fertility awareness-based methods of family planning: A review of effectiveness for avoiding pregnancy using SORT.|journal=Osteopathic Family Physician |volume=5 |issue=1 |pages=2–8 |date=January–February 2013|doi=10.1016/j.osfp.2012.09.002}}</ref>

===Advantages===
* There are no drug-related side effects to fertility awareness.<ref name="FABM"/>
* FA can be free or have a very low up-front cost. Users may employ a coach, use computer software, or buy a chart, calendar, or basal thermometer. The direct costs are low when compared to other methods.
* FA can be used with barrier contraception so that intercourse may continue through the fertile period. Unlike barrier use without FA, practicing FA can allow couples to use barrier contraception only when necessary.
* FA can be used to immediately switch from pregnancy avoidance to pregnancy planning if the couple decides it is time to plan for conception.

===Disadvantages===
*Use of a barrier or other backup method is required on fertile days; otherwise the couple must abstain. To reduce pregnancy risk to below 1% per year, there are an average of 13 days where abstinence or backup must be used during each cycle.<ref name="german study">{{cite journal  |vauthors=Frank-Herrmann P, Heil J, Gnoth C, etal |title=The effectiveness of a fertility awareness based method to avoid pregnancy in relation to a couple's sexual behaviour during the fertile time: a prospective longitudinal study |journal=Hum. Reprod. |volume=22 |issue=5 |pages=1310–9 |year=2007 |pmid=17314078 |doi=10.1093/humrep/dem003|doi-access=free }}</ref> For women with ''very'' irregular cycles—such as those common during breastfeeding, perimenopause, or with hormonal diseases such as [[Polycystic ovary syndrome|PCOS]]—abstinence or the use of barriers may be required for months at a time.
*Typical use effectiveness is lower than most other methods.<ref name=Trussell2009>{{cite journal|journal = Contraception|year = 2009| volume=79|issue = 1| pmid=19041435| pages = 5–14| title = Cost effectiveness of contraceptives in the United States |author1=James Trussell |author2=Anjana Lalla |author3=Quan Doan |author4=Eileen Reyes |author5=Lionel Pinto |author6=Joseph Gricar | doi=10.1016/j.contraception.2008.08.003| pmc=3638200}}</ref>
*Fertility awareness does not protect against [[sexually transmitted disease]].<ref name="uihc">{{cite web |year=2012 | url=https://brown.edu/Student_Services/Health_Services/Health_Education/sexual_health/safer_sex_and_contraceptives/fertility_awareness_method.php#3 | title =Fertility Awareness Method | work =Brown University Health Education Website | publisher =Brown University |access-date=2012-12-11 }}</ref>

===Effectiveness===
The effectiveness of fertility awareness, as of most forms of [[birth control|contraception]], can be assessed two ways. ''Perfect use'' or ''method'' effectiveness rates only include people who follow all observational rules, correctly identify the fertile phase, and refrain from unprotected intercourse on days identified as fertile. ''Actual use'' or ''typical use'' effectiveness rates include all women relying on fertility awareness to avoid pregnancy, including those who fail to meet the "perfect use" criteria. Rates are generally presented for the first year of use.<ref name="hatcher">{{cite book | first=RA | last=Hatcher | author2=Trussel J | author3=Stewart F | year=2000 | title=Contraceptive Technology | edition=18th | publisher=Ardent Media | location=New York | isbn=0-9664902-6-6 | url=http://www.contraceptivetechnology.com/table.html | display-authors=etal | access-date=2008-01-01 | archive-date=2008-05-31 | archive-url=https://web.archive.org/web/20080531095926/http://www.contraceptivetechnology.com/table.html }}</ref> Most commonly, the [[Pearl Index]] is used to calculate effectiveness rates, but some studies use [[decrement table]]s.<ref>{{cite book | first=John | last=Kippley |author2=Sheila Kippley | year=1996 | title=The Art of Natural Family Planning | edition=4th addition | publisher=The Couple to Couple League | location=Cincinnati, OH | isbn=0-926412-13-2 | page=141 }}</ref>

The failure rate of fertility awareness varies widely depending on the system used to identify fertile days, the instructional method, and the population being studied. Some studies have found actual failure rates of 25% per year or higher.<ref>{{cite journal  |vauthors=Wade ME, McCarthy P, Braunstein GD, etal | title= A randomized prospective study of the use-effectiveness of two methods of natural family planning | journal=American Journal of Obstetrics and Gynecology |date=October 1981 | volume=141 | issue=4 | pages=368–376 | pmid=7025639 | doi = 10.1016/0002-9378(81)90597-4 }}</ref><ref>{{cite journal  |vauthors=Medina JE, Cifuentes A, Abernathy JR, etal | title= Comparative evaluation of two methods of natural family planning in Colombia | journal=American Journal of Obstetrics and Gynecology |date=December 1980 | volume=138 | issue=8 | pages=1142–1147 | pmid=7446621 | doi=10.1016/S0002-9378(16)32781-8 }}</ref><ref>{{cite journal | author=Marshall J | title= Cervical-mucus and basal body-temperature method of regulating births: field trial | journal=Lancet |date=August 1976 | volume=2 | issue=7980 | pages=282–283 | pmid=59854 | doi=10.1016/S0140-6736(76)90732-7 | s2cid= 7653268 }}</ref> At least one study has found a failure rate of less than 1% per year with continuous intensive coaching and monthly review,<ref name="billings" /> and several studies have found actual failure rates of 2%–3% per year.<ref name="german study" /><ref>{{cite journal  |vauthors=Frank-Herrmann P, Freundl G, Baur S, etal | title= Effectiveness and acceptability of the sympto-thermal method of natural family planning in Germany | journal=American Journal of Obstetrics and Gynecology |date=December 1991 | volume=165 | issue=6 Pt 2 | pages=2052–2054 | pmid=1755469 | doi=10.1016/s0002-9378(11)90580-8}}</ref><ref>{{cite conference | vauthors=Clubb EM, Pyper CM, Knight J | title=A pilot study on teaching natural family planning (NFP) in general practice | book-title=Proceedings of the Conference at Georgetown University, Washington, DC | year=1991 | url=http://www.fertilityuk.org/nfps822.html | archive-url=https://web.archive.org/web/20070323160200/http://www.fertilityuk.org/nfps822.html | archive-date=2007-03-23 }}</ref><ref>{{cite journal  |vauthors=Frank-Herrmann P, Freundl G, Gnoth C, etal | title= Natural family planning with and without barrier method use in the fertile phase: efficacy in relation to sexual behavior: a German prospective long-term study | journal=Advances in Contraception | date=June–September 1997 | volume=13 | issue=2–3 | pages=179–189 | pmid=9288336 | doi= 10.1023/A:1006551921219 | s2cid= 24012887 }}</ref>

When used correctly and consistently (i.e., with perfect use) with ongoing coaching, under study conditions some studies have found some forms of FA to be 99% effective.<ref name="billings">[http://www.woomb.org/omrrca/bulletin/vol27/no4/chinaEvaluation.html Evaluation of the Effectiveness of a Natural Fertility Regulation Programme in China] {{webarchive|url=https://web.archive.org/web/20070427204752/http://www.woomb.org/omrrca/bulletin/vol27/no4/chinaEvaluation.html |date=2007-04-27 }}: Shao-Zhen Qian, et al. Reproduction and Contraception (English edition), in press 2000.</ref><ref>{{Cite journal | last1 = Ecochard | first1 = R. | last2 = Pinguet | first2 = F. | last3 = Ecochard | first3 = I. | last4 = De Gouvello | first4 = R. | last5 = Guy | first5 = M. | last6 = Huy | first6 = F. | year = 1998 | title = Analysis of natural family planning failures. In 7007 cycles of use | journal = Contraception, Fertilité, Sexualité | volume = 26 | issue = 4| pages = 291–6 |pmid = 9622963}}</ref><ref name="creighton2">{{Cite journal | last1 = Hilgers | first1 = T.W. | last2 = Stanford | first2 = J.B. | year = 1998 | title = Creighton Model NaProEducation Technology for avoiding pregnancy. Use effectiveness | journal = Journal of Reproductive Medicine | volume = 43 | issue = 6| pages = 495–502 | pmid = 9653695 }}</ref><ref name="creighton">{{Cite journal | doi = 10.1001/archfami.8.5.391 | last1 = Howard | first1 = M.P. | last2 = Stanford | first2 = J.B. | year = 1999 | title = Pregnancy probabilities during use of the Creighton Model Fertility Care System | journal = Archives of Family Medicine | volume = 8 | issue = 5| pages = 391–402 | pmid = 10500511 }}</ref>

From ''Contraceptive Technology'':<ref name="conttech">James Trussell et al. (2000) "Contraceptive effectiveness rates", ''Contraceptive Technology''&nbsp;— 18th Edition, New York: Ardent Media. On-press.</ref>

* Post-ovulation methods (i.e., abstaining from intercourse from menstruation until after ovulation) have a method failure rate of 1% per year.
* The symptothermal method has a method failure rate of 2% per year.
* 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.

===Reasons for lower typical-use effectiveness===
Several factors account for typical-use effectiveness being lower than perfect-use effectiveness:
* conscious user non-compliance with instructions (having unprotected intercourse on a day identified as fertile)
* mistakes on the part of those providing instructions on how to use the method (instructor providing incorrect or incomplete information on the rule system)
* mistakes on the part of the user (misunderstanding of rules, mistakes in charting)

The most common reason for the lower actual effectiveness is not mistakes on the part of instructors or users, but conscious user non-compliance<ref name="german study" /><ref name="creighton" />—that is, 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.

==To achieve pregnancy==

===Intercourse timing===
Timing intercourse with a person's estimated 'fertile window' is a practice sometimes called 'timed intercourse'.<ref name="Gibbons-2023">{{Cite journal |last1=Gibbons |first1=Tatjana |last2=Reavey |first2=Jane |last3=Georgiou |first3=Ektoras X |last4=Becker |first4=Christian M |date=2023-09-15 |editor-last=Cochrane Gynaecology and Fertility Group |title=Timed intercourse for couples trying to conceive |journal=Cochrane Database of Systematic Reviews |language=en |volume=2023 |issue=9 |article-number=CD011345 |doi=10.1002/14651858.CD011345.pub3 |pmc=10501857 |pmid=37709293}}</ref> The effectiveness of timed intercourse is not entirely clear, however, timed intercourse using urine tests that predict ovulation may help improve the rate of pregnancy and live births for some couples trying to conceive such as those who have been trying for less than 12-months and who are under 40 years old.<ref name="Gibbons-2023" /> It is not clear from medical evidence if timed intercourse improves the rate of ultra-sound confirmed pregnancies and it is also not clear if timed intercourse has an effect on a person's level of stress or their quality of life.<ref name="Gibbons-2023" /> [[Pregnancy rate#Pregnancy rate for sexual intercourse|Pregnancy rates for sexual intercourse]] are also affected by several other factors. Regarding frequency, there are recommendations of sexual intercourse every 1 or 2 days,<ref>{{cite web |date=2016-11-02 |title=How to get pregnant |url=https://www.mayoclinic.org/healthy-lifestyle/getting-pregnant/in-depth/how-to-get-pregnant/art-20047611 |access-date=2018-02-16 |website=[[Mayo Clinic]]}}</ref> or every 2 or 3 days.<ref>{{cite web |title=Fertility problems: assessment and treatment, Clinical guideline [CG156] |url=https://www.nice.org.uk/guidance/cg156/ifp/chapter/trying-for-a-baby |access-date=2018-02-16 |website=[[National Institute for Health and Care Excellence]]|date=20 February 2013 }} Published date: February 2013. Last updated: September 2017</ref> Studies have shown no significant difference between different [[sex positions]] and pregnancy rate, as long as it results in [[ejaculation]] into the [[vagina]].<ref name="americanpregnancy">{{cite web |author=Dr. Philip B. Imler & David Wilbanks |title=The Essential Guide to Getting Pregnant |url=http://americanpregnancy.org/getting-pregnant-ebook/p7M7O0q1c71703C/gettingpregnant.pdf |archive-url=https://web.archive.org/web/20180601033115/http://americanpregnancy.org/getting-pregnant-ebook/p7M7O0q1c71703C/gettingpregnant.pdf |archive-date=2018-06-01 |access-date=2018-02-16 |website=American Pregnancy Association}}</ref> Social science research has found that timing intercourse can become a gendered 'chore' in heterosexual married couples trying to conceive, with women tracking their ovulation cycles and dictating to their husbands when they should have sexual intercourse.<ref>{{cite journal |vauthors=Brown E |year=2022 |title=Less Like Magic, More Like a Chore: How Sex for the Purpose of Pregnancy Becomes a Third Shift for Women in Heterosexual Couples |journal=Sociological Forum |volume=37 |issue=2 |pages=465–85 |doi=10.1111/socf.12803 |s2cid=247329309}}</ref>

===Problem diagnosis===
Regular menstrual cycles are sometimes taken as evidence that a woman is ovulating normally, and irregular cycles as evidence she is not.<ref>{{Cite web |title=Infertility fact sheet: What causes infertility in women? |website=womenshealth.gov |publisher=U.S. Department of Health and Human Services, Office on Women's Health |url=http://www.womenshealth.gov/publications/our-publications/fact-sheet/infertility.cfm#f |access-date=2012-12-11 |archive-url=https://web.archive.org/web/20121102032112/http://womenshealth.gov/publications/our-publications/fact-sheet/infertility.cfm#f |archive-date=2012-11-02}} ''"Some signs that a woman is not ovulating normally include irregular or absent menstrual periods."''<br />
{{Cite web |title=Female Infertility |website=Adult Health Advisor |year=2012 |url=http://www.ihacares.com/index.cfm/HealthAdvisors/AdultHealthAdvisor/crs-aha-aha_obg_female.infertility/ |archive-url=https://web.archive.org/web/20101229161028/http://www.ihacares.com/index.cfm/HealthAdvisors/AdultHealthAdvisor/crs-aha-aha_obg_female.infertility/ |archive-date=2010-12-29}}. ''"A woman who is not ovulating normally may have irregular or missed menstrual periods."''<br />
{{Cite web |title=Is Clomid Right For You? |website=JustMommies.com |year=2007 |url=http://www.justmommies.com/articles/clomid-and-ovulation.shtml }}. ''"If you have an irregular cycle there is a good chance you are not ovulating normally."''</ref>  However, many women with irregular cycles do ovulate normally, and some with regular cycles are actually anovulatory or have a luteal phase defect. Records of basal body temperatures, especially, but also of cervical mucus and position, can be used to accurately determine if a woman is ovulating, and if the length of the post-ovulatory (luteal) phase of her menstrual cycle is sufficient to sustain a pregnancy.

Fertile cervical mucus is important in creating an environment that allows sperm to pass through the cervix and into the fallopian tubes where they wait for ovulation.  Fertility charts can help diagnose hostile cervical mucus, a common cause of infertility. If this condition is diagnosed, some sources suggest taking [[guaifenesin]] in the few days before ovulation to thin out the mucus.<ref>Weschler (2002), p. 173.</ref>

===Pregnancy testing and gestational age===
[[Pregnancy test]]s are not accurate until 1–2 weeks after ovulation. Knowing an estimated date of ovulation can prevent a woman from getting false negative results due to testing too early. Also, 18 consecutive days of elevated temperatures means a woman is almost certainly pregnant.<ref>Weschler (2002), p.316</ref> Estimated ovulation dates from fertility charts are a more accurate method of estimating [[Embryonic age|gestational age]] than the traditional pregnancy wheel or last menstrual period (LMP) method of tracking menstrual periods.<ref>Weschler (2002), pp.3-4,155-156, insert p.7</ref> Because of high rates of very early [[miscarriage]] (25% of pregnancies are lost within the first six weeks since the woman's [[last menstrual period]]), the methods used to detect pregnancy may lead to bias in conception rates. Less-sensitive methods will detect lower conception rates, because they miss the conceptions that resulted in early pregnancy loss.{{Citation needed|date=September 2023}}

==See also==
*[[Billings ovulation method]]
*[[Creighton Model FertilityCare System]]
*[[Fertility monitor]]
*[[Lactational amenorrhea method]]
*[[Kindara]]
*[[TwoDay Method]]

==References==
{{Reflist|30em}}

==Further reading==
* {{cite book |author=Toni Weschler |title=Taking Charge of Your Fertility |publisher=Collins |location=New York |year=2006 |isbn=0-06-088190-9 |edition=10th Anniversary |url=https://archive.org/details/takingchargeofy000wesc }}
* {{cite book |author1=John F. Kippley |author2=Sheila K. Kippley |title=The Art of Natural Family Planning |publisher=Couple to Couple League International |location=Cincinnati, OH |year=1996 |isbn=0-926412-13-2 |edition=Fourth}}

{{Reproductive health}}
{{Menstrual cycle}}
{{Pregnancy}}
{{Birth control methods}}

{{DEFAULTSORT:Fertility Awareness}}
[[Category:Fertility awareness| ]]