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Contraception health centre

Natural family planning (fertility awareness)

What is natural family planning?

Natural family planning is a method of contraception also known as fertility awareness, or the rhythm method.

Using this method, a woman learns to recognise the days she is fertile, then avoids having sex before and during those fertile days.

This method does not work for all couples. Women who have regular menstrual cycles and who are very careful about when they have sex usually find it to be effective. It can be less effective for women who have irregular periods.

Natural family planning is used by around 3% of women in most of the UK, but around 5% in Northern Ireland.

How does the rhythm method work?

Aspects of the rhythm method include tracking body temperature changes and vaginal discharge (secretions or fluid from the vagina) and length of menstrual cycle to pinpoint which days you are fertile.

Changes in these fertility indicators can help identify fertile time. Fertility monitoring devices designed to assist with becoming pregnant can also be used to help identify non-fertile days.

A woman's fertile time is around eight or nine days of each menstrual cycle. An egg can live for up to 24 hours and sperm can survive inside a woman's body for up to seven days. More than one egg may be released during ovulation, usually within 24 hours of the first egg.

Having sex as many as seven days before ovulation can still result in a pregnancy.

Ask your doctor or family planning specialist how best to use the rhythm method.

How effective is the rhythm method?

The Family Planning Association (FPA) says the effectiveness of natural family planning depends on factors such as a woman's age and how often she has sex. It says if instructions are followed carefully, natural family planning can be 99% effective.

Other contraceptive methods, such as male condoms, would be required for sex during the fertile times.

It stresses the technique is more effective when it has been taught by a specialist natural family planning teacher, and recommends using more than one indicator of fertility.

The FPA says this method may not be effective until it is fully understood, which may take between three and six menstrual cycles.

It also requires good record keeping and any awareness of anything that may affect fertility indicators, such as stress or illness.

Natural family planning can be more difficult for women with irregular cycles, those who have recently stopped the Pill or other hormonal contraception, women who have recently had a baby, abortion or miscarriage, women who are breastfeeding or after or near menopause.

What are the advantages of natural family planning?

Some women chose natural family planning in order to avoid chemicals or contraceptive devices and to avoid physical side effects. It may also be a religious or cultural choice.

As well as helping to avoid a pregnancy, charting fertility can also help to plan a pregnancy.

The awareness can also help a women better spot any abnormal vaginal secretions which may be a sexual health concern.

Does the rhythm method protect against sexually transmitted infections?

No. The rhythm method does not protect against sexually transmitted infections (STIs). 

The male condom provides the best protection from STIs.

WebMD Medical Reference

Medically Reviewed by Dr Rob Hicks on August 09, 2016

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