What are fertility awareness contraceptive methods?

Fertility awareness methodsFertility awareness contraceptive methods are methods of preventing pregnancy which rely on a woman monitoring her fertility throughout the menstrual cycle and avoiding sex on days of the cycle in which she is fertile. These methods are also known as periodic abstinence methods and natural contraceptive methods. Methods for monitoring fertility are either:

  1. Calendar based, that is, based on keeping a menstrual cycle calendar (which commences on the first day of menstrual bleeding) and determining fertility according to the number of days which have passed since last menstrual bleeding; or
  2. Symptom based, that is, monitoring body changes which indicate changing levels of hormones and determining fertility based on these changes.

Effective use of either calendar or symptom based methods is highly dependent on both the woman using them and her partner’s willingness and ability to avoid penetrative vaginal sex, or use another contraceptive method during fertile periods of the cycle. Periodic abstinence or alternative contraceptive methods are an important part of the method.

How do fertility awareness contraceptive methods work?

Fertility awareness methods work by preventing fertilisation, that is, a sperm and egg coming into contact with each other in a woman’s uterus or fallopian tubes. Each menstrual cycle an egg is released from the ovaries, and travels through the fallopian tubes and into the uterus. If it is not fertilised by a sperm, it is expelled from the uterus, along with the lining of the uterus (i.e. menstrual blood) within 24 hours. In order for sperm to fertilise the egg, it must be alive in the uterus at the same time as an egg, that is, it must be alive in the uterus just after ovulation. Sperm can stay alive in the uterus for up to five days, and so a woman can become pregnant if she has sex in the five days prior to ovulation, or the 24 hour period in which ovulation takes place.

Ovulation occurs at roughly the same time in each menstrual cycle (around the middle of the cycle), and a number of observable changes take place in a woman’s body in the lead up to and following ovulation. These include changes to the texture and quantity of her cervical mucus and body temperature changes. By monitoring these changes, or by tracking the days of her menstrual cycle to identify the mid point, a woman can work out when she is and is not fertile.

The woman must then abstain from penetrative sex or use another contraceptive method during the fertile period, to ensure that sperm does not enter her uterus while she is fertile.

Who can and cannot use fertility awareness methods?

Fertility based awareness methods are suitable for most women although some women may have difficulty using some of the methods (e.g. women with irregular length menstrual cycles). Some women may also need to wait a short while before they can use fertility awareness methods (e.g. those who have recently given birth).

Calendar based methods

For calendar methods, women who may not be able to use the methods or may have to wait to use them include:Calendar based methods

  • Young women who have just started menstruating and who may not yet have established a regular cycle. These women should only use calendar based methods with caution;
  • Women who are approaching menopause and experiencing irregular menstrual cycles as a result. These women should also use calendar based methods with caution;
  • Women who have recently given birth. These women should wait until they are once again experiencing regular menstrual cycles before using calendar based methods. The methods should be used with caution for the first three menstrual cycles;
  • Women who are breastfeeding. These women should wait until their menstrual cycle returns and use calendar based methods with caution for the first three cycles;
  • Women who have experienced miscarriage or have terminated a pregnancy. These women should wait until the start of their next menstrual cycle to begin using calendar based methods;
  • Women using any form of mood altering drug (e.g. anti-depressants). These women should delay using calendar based methods until they finish the medication, or use with caution if necessary;
  • Women on long-term antibiotic or non steroidal anti-inflammatory drugs. These women should also delay using calendar based methods until they finish the medication, or use with caution if necessary;
  • Women who have been using the hormonal contraceptive. These women should wait until their next menstrual cycle to begin using calendar methods.

Women who would like to use calendar based methods but must wait for a period of time to do so, and should therefore abstain from sex or use another contraceptive method while they are waiting, for example male or female condoms.

For more information, see Calendar Based Methods of Contraception

Symptom based methods

For symptom based methods, women who should delay use or use the methods cautiously include:

  • Women who have just experienced a miscarriage or pregnancy termination – symptom based methods should be used with caution;
  • Women who experience irregular menstrual cycles, for example those approaching menopause – symptom based methods should be used with caution;
  • Women who have a health condition which raises their body temperature should ideally wait until the condition has been treated to use symptom based methods;
  • Women who have recently given birth should delay using symptom based methods until regular menstrual cycles return, typically six months for breastfeeding women and four weeks for non-breastfeeding women. The methods should then be used with caution for the first three months;
  • Women with irregular vaginal bleeding should delay until regular vaginal bleeding returns;
  • Women with unusual vaginal discharge should delay use of these methods until the discharge is treated and goes away;
  • Women using mood altering drugs, some antibiotics or non-sterioidal anti-inflammatory drugs should use symptom based methods with caution or delay until drug use ceases).

Women who need to delay use of symptom based methods should use an alternative contraceptive method or abstain from sex while they are waiting.

For more information, see Cervical Mucus Monitoring Methods of Birth Control

Who uses fertility awareness methods?

Fertility awareness methodsThe Sex in Australia survey, a nationally representative survey of sexual practices, reported that 4.4% of Australian women use fertility awareness methods for contraception.

Women from non-English speaking backgrounds and those who live with regular partners are more likely to use this method than their English speaking and non-cohabiting counterparts.

Women from remote areas were less likely to use fertility awareness methods than women from regional or urban areas.

Overview of types of fertility awareness methods

There are numerous ways in which a woman can monitor her fertility. Each is a different contraceptive method, which use very different systems for tracking fertile and infertile times in the cycle. The most common include:

  • Symptom based methods:
    • Cervical mucus monitoring methods (including the Billings or ovulation method and the two days method) – these methods rely on the woman examining her cervical mucus on a daily basis in order to identify when she is and is not fertile;
    • Basal body temperature monitoring method – is a contraceptive method which relies on the woman measuring her basal body temperature everyday, in order to identify the end of the fertile phase of her menstrual cycle;
    • Symptothermal method – is a method in which both basal body temperature and cervical secretions are monitored simultaneously to determine fertility;
  • Calendar based methods;
    • Standard days method – is a method in which a woman with standard length cycles counts the days from the commencement of menstrual bleeding. Fertile and infertile periods are calculated based on a standard length menstrual cycle and the number of days elapsed;
    • Calendar rhythm method – a method in which a woman with non-standard length cycles counts the days from the commencement of bleeding. Fertile and infertile periods are calculated based on the average length of her menstrual cycle in the previous six months.

Important points regarding the use of fertility awareness methods

Fertility awareness methodsWomen who wish to use fertility awareness methods must ensure that they are properly informed regarding the use of these methods. They may wish to visit a family planning clinic or their doctor to discuss the benefits and limitations of each method, which include:

  • Need for periodic abstinence or alternative contraception: fertility awareness methods only work if the woman abstains or uses alternative contraceptives during the fertile period. This means fairly long periods of sexual abstinence or the need to use an alternative contraceptive method. As sexual abstinence and the use of some barrier methods are highly dependent on the cooperation of the woman’s sexual partner, women should discuss how the method works with their partner or take them to the family planning clinic or doctor so they can also receive information about fertility awareness methods from a health professional.
  • Need for accurate monitoring: fertility awareness methods require daily monitoring or recording. Unless this is performed accurately, the effectiveness of the method will decline.
  • Risk of sexually transmitted infection: women should be aware that fertility awareness methods do not protect against sexually transmitted infections (STIs).

Women who use fertility awareness methods and wish to have sex during the fertile periods of their cycle should discuss alternative methods of contraception with their healthcare provider. They should be aware that emergency contraceptives can reduce the chance of pregnancy for up to five days after unprotected intercourse in the fertile period and are available over the counter in Australian pharmacies.

Effectiveness of fertility awareness methods

Fertility awareness methods can be highly effective methods of family planning. When used correctly they prevent pregnancy in 91-99% of cases, depending on the method of fertility monitoring chosen. Basal body temperature monitoring is the most effective (99%) fertility awareness method when used correctly, while the calendar rhythm method is the least effective (91%). Women using these methods should also be aware that the methods are more effective for users who abstain from sex during their fertile periods, compared to those who use alternative contraceptive methods at this time.

They should also be aware that in practice, fertility awareness methods are far less effective. An estimated one in four women become pregnant in the first year of using fertility awareness methods (i.e. these methods are 75% effective in preventing pregnancy). The main reason this is because women using them do not avoid sex or use alternative contraceptive methods during the fertile period of their menstrual cycle.

Benefits of fertility awareness methods

Fertility awareness methodsFertility awareness methods are natural methods of family planning and therefore do not have any adverse health effects for women. Women also report liking fertility awareness methods as using the methods increases their awareness about their bodies and fertility throughout the menstrual cycle.

In addition they do not rely on any special devices or medications, so women who have concerns about introducing foreign substances or devices to their bodies may like this method more than other methods of family planning. Women who are unable to use other forms of contraception for religious or cultural reasons may also find these methods highly acceptable.

Fertility awareness methods also provide women with a contraceptive method which they do not depend on a health professional to provide, and thus they can commence using the method at any time once they have been instructed about how to monitor their fertility.

Limitations of fertility awareness method

Fertility awareness methods rely on the cooperation of the woman’s partner and his willingness to either avoid sex or use an alternative contraceptive method at fertile times in the cycle. This often means long periods of abstinence.

To be used effectively the methods also rely on women accurately monitoring the stage of their menstrual cycle or body changes. Some women may be uncomfortable with monitoring methods which require them to touch their genitals (e.g. cervical mucus monitoring). Other women may find it difficult to monitor their cycle or body changes on a daily basis (e.g. because they are forgetful).

Fertility awareness based methods provide no protection against sexually transmitted infections (STIs). Women who are at risk of STI as well as pregnancy should, if possible, use male or female condoms in addition to fertility awareness methods.


More information 

Contraception For more information on different types of contraception, male and female anatomy and related health issues, see Contraception.


  1. World Health Organisation. Family Planning: A global handbook for providers. 2007. [cited 2009, June 20] Available from:  www.who.int/entity/reproductivehealth/publications/family_planning/en/
  2. Germano, E. Jenning, V. New approaches to fertility awareness based methods: incorporating the standard days and two days methods into practice. J Midwifery Women’s Health. 2006;51:471-7.
  3. Richters, J. Grulich, A.E. de Visser, R.O. et al. Sex in Australia: Contraceptive Practices in a representative sample of women. Aust NZ J Pub Health. 2003;27:210-6.
  4. International Planned Parenting Federation. Fertility Awareness. 2009. [coted 2009, November 5] Available from: http://www.plannedparenthood.org/health-topics/birth-control/fertility-awareness-4217.htm

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