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Natural Family Planning

What is it and how does it work?

Natural family planning (NFP) helps women recognise the fertile and infertile times of their menstrual cycles to plan or avoid a pregnancy. A woman's fertile time (when she can get pregnant) lasts for eight to nine days in each menstrual cycle. An egg lives for up to 24 hours and is released 12 to 16 days before the next period. Sperm can live for up to seven days. This means if you have sex seven days before you ovulate (release an egg), you could get pregnant.

NFP teaches you to recognise and record the different natural signs or indicators of fertility each day of your menstrual cycle. It must be taught by a specialist teacher to be effective. If used according to teaching and instructions, it's up to 98 per cent effective. This means that using this method as contraception, up to two women in 100 will get pregnant in a year.


NFP is most effective when two or more fertility indicators are used to identify the fertile time.

  • Temperature. Your body temperature rises after ovulation. If you record your temperature every day when you wake up, you'll know when ovulation has happened.

  • Cervical secretions. During the menstrual cycle, changes occur in the cervical mucus. These cause feelings of dryness, moistness or wetness in the vagina. When the secretions are clear and slippery, you're at your most fertile.

  • Other changes. The position of the cervix changes during the menstrual cycle. Some women notice pain around ovulation, changes to their moods, skin, breasts or sexual desire.


  • There are no physical side effects.

  • Effective if well taught and instructions are followed.

  • No hormones or physical devices are used.

  • Improves understanding of fertility and how the body works.

  • Couples share responsibility.

  • Can be used to plan or avoid pregnancy.


  • Takes up to six cycles to learn and daily records must be kept.

  • Requires commitment of both partners.

  • Sex must be avoided (or a barrier method used) during the fertile time.

  • Illness, stress or travel make it more difficult to recognise signs of fertility.\

Can anyone use it?

Most people can use NFP if they receive good teaching and support. It's acceptable to all faiths and cultures.

General comments

Fertility devices are now available that measure changes in temperature, urine or saliva to predict fertility. These can be bought from pharmacies. They're not as effective as using taught NFP methods.

Where to get advice

Family planning clinics or GPs often don't teach NFP. For a specialist teacher,

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