What are fertility awareness contraceptive methods?
Fertility 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:
- 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
- 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).
For calendar methods, women who may not be able to use the methods or may have to wait to use them include:
- 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
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
The 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.
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.