Fertility Awareness Methods

  • 76-99.5 % Effective
  • No STI Protection
  • Daily

What are fertility awareness methods (natural family planning)?

Fertility awareness methods (natural family planning) avoid sex around the fertile time of the menstrual cycle (the time pregnancy is most likely to happen).

How effective are fertility awareness methods?

Depending on the method used to track the fertile time and when to avoid sex, fertility awareness methods can be over 99% effective at preventing pregnancy. Some methods might only by 76% effective at preventing pregnancy.

How do fertility awareness methods work?

For pregnancy to occur, sperm must fertilise a mature egg. During each menstrual cycle, an egg is released from one of the ovaries, this is called ovulation. The days near ovulation are fertile days – when pregnancy is most likely to occur.

An egg lives for around 12 – 24 hours after ovulation and sperm live about 6 days after sex. This means a person who menstruates is usually fertile for around 7 days of every menstrual cycle: the 5 days before ovulation, the day of ovulation and the day or 2 after.

Avoiding sex (or using other forms of contraception) on these days is one method to prevent pregnancy.

How to use fertility awareness methods

Using fertility awareness methods needs a very good understanding of the menstrual cycle and careful daily monitoring of bodily changes. Before using fertility awareness methods, it is recommended you see a health care professional who has training in this area.

To work out the fertile time and when to avoid sex, the following combination of bodily changes can be recorded daily:

  • Thickness or wetness of the sticky fluid (mucus) made by the cervix (opening of the womb).
Illustration of mucus in cervix
  • Changes in your body temperature
Illustration of person measuring body temperature
  • Your menstrual cycle pattern (the number of days you have menstrual bleeding (period) and the number days you do not bleed before your next menstrual period).
Illustration of calendar for monitoring menstrual cycle

When does it start to be effective?

It may take time to understand and recognise changes in the menstrual cycle. Dedication to daily tracking will be needed to identify the fertile time. It may take several months before feeling confident to use fertility awareness methods as contraception.

What stops fertility awareness methods from working?

  • Having sex in the fertile time.
  • Any changes to the menstrual cycle can make it hard to track the fertile time and when to avoid sex. Changes may occur due to many factors such as sickness, anxiety or stress, travel, losing or gaining a lot of weight, exercising a lot and certain medications. Some people have irregular menstrual cycles or infrequent menstrual periods which can be difficult to track. This includes people who are breastfeeding or who are close to menopause.

What is good about fertility awareness methods?

  • It fits in with many religious or cultural beliefs.
  • Understanding the fertile times can also be used to help get pregnant.
  • It does not involve synthetic hormones or chemicals.

Are there any side effects from using fertility awareness methods?

There are no side effects from using fertility awareness methods.

Can fertility awareness methods cause any serious health problems?

There are no serious health risks from using fertility awareness methods.

Reasons why fertility awareness methods might not be a good option:

  • There could be a health risk to you or the baby if you got pregnant. This is because the risk of pregnancy when using fertility awareness methods is higher than with many other types of contraception.
  • If you feel like having sex around ovulation time (before or when you release an egg).
  • You have irregular or infrequent periods.
  • You are using a medication that disrupts production of cervical mucus.
  • You have difficulty with daily monitoring of menstrual cycles and symptoms.

What if I had sex without using fertility awareness methods?

If you or your partner do not want to be pregnant, you might need emergency contraception, if you had sex without using fertility awareness methods or other contraception (check with your doctor, nurse or pharmacist).

What if pregnancy happens while using fertility awareness methods?

It is safe to continue the pregnancy or to have an abortion.

Can I use fertility awareness methods after I have had a baby?

Fertility awareness methods are difficult to use until menstrual periods return to a regular cycle. Ovulation usually occurs before menstrual bleeding, which means a person is fertile before the first menstrual period after having a baby. Breastfeeding can also change the menstrual cycle and effect fertility.

What else should I know about fertility awareness methods?

  • Requires careful monitoring of bodily changes every day.
  • There will be days during the menstrual cycle when you cannot have unprotected sex if you want to prevent pregnancy.
  • Fertility awareness methods do not protect from sexually transmissible infections (STIs).
  • Fertility awareness methods are one of many types of contraception. See other contraceptive options

You might be interested in watching:

Where to get more information and support

If you are using the internet for information, only use reliable and reputable websites, such as the ones provided above.

This website and any related materials are for general information purposes only and should not be relied on as (or in substitution for) medical or other professional advice. You should seek specific medical or professional advice for your individual circumstances.

Copyright ©
The copyright for material on this website is owned by Sexual Health Victoria (or, in some cases, by third parties) and is subject to the Copyright Act 1968. We permit you to reproduce or communicate our copyright material if you are a not-for-profit educational organisation, for the purpose of providing the information to your students provided that you include any disclaimers associated with that material. Any other reproduction or communication of our material requires our prior consent, via our consent form which you can complete and submit.

Last updated: 11 June 2021