Natural Family Planning

Also called fertility awareness, natural family planning is an approach to contraception that involves a woman monitoring her fertility signals to calculate when she’s likely to get pregnant. Keep reading to discover more about the different natural family planning methods that people use, as well as their advantages and disadvantages.


What is natural family planning and how does it work?

The term natural family planning describes different ways in which women prevent or plan pregnancy based on their observations of certain fertility indicators. This approach can be used to prevent pregnancy by changing sexual behaviour during a woman’s fertile window. For example, during this time, women can use barrier methods of contraception such as condoms, or abstain from vaginal intercourse.

There are two main types of natural family planning methods. They are called fertility awareness methods and lactational amenorrhoea methods. Both methods can be highly effective if used consistently and correctly. Any decision to use a natural family planning method for contraception should be made in consultation with your doctor or a natural family planning expert. We discuss the approaches in more detail below.


Fertility awareness methods

These methods involve calculating when a woman is least (or most) fertile by keeping track of and recording fertility indicators. These indicators include:

The length of the menstrual cycle

You can calculate how long your menstrual cycle lasts and use this to estimate the dates on which you’re likely to ovulate and the fertile days around this. Your cycle starts on the first day of your period and lasts until the day prior to your next period. On average, cycles last for 28 days, but cycles ranging from 21 to 40 days are considered within the normal range.

Part way through your cycle, one of your ovaries releases an egg, which moves down the fallopian tube. This usually happens around 10 to 16 days before your next period. The egg lives for around 24 hours once it is released, and for pregnancy to occur, it must meet a sperm within this timeframe. Occasionally, a second egg is released within a day of the first. This means that it’s possible to conceive up to 2 days after ovulation. It’s also important to know that sperm can live inside a woman’s body for as long as 7 days. So, if you have sex up to 7 days before you ovulate, you may still get pregnant. In total, this means the fertile window lasts for around 9 days, but this can vary from person to person. 

By monitoring your cycle, you can work out when you’re most likely to be fertile and adapt your sexual activity around this. However,  because your ovulation dates can vary over time, to be as accurate as possible in your predictions, you should monitor your cycle for at least 12 months before using a natural family planning method for contraception - and you should consult your doctor or a family planning specialist before making a decision to use this method.


Basal body temperature

Another fertility awareness method involves keeping track of your body temperature. After ovulation, there is a slight increase in body temperature.

When you see 3 successive days when your temperature is higher than it had been for all of the preceding 6 days, it’s likely that you’re no longer in your fertile window. The rise in temperature could be very small. It’s usually roughly 0.2°C. An expert in natural family planning should be consulted before using this method of contraception.


Cervical secretions

Your cervical secretions change in texture and amount at different times throughout your cycle. In the few days following your period, you probably won’t produce much mucus. After this, as hormone levels rise in preparation for ovulation, you’ll start to notice more mucus that’s moist, white and creamy. This could signal the beginning of your fertile window.

Shortly before ovulation, the mucus will become clearer, wetter and more slippery - similar to raw egg white. This can indicate you’re at your most fertile. After this, the mucus should return to being sticky and thick, and after a few days you will be past your fertile window. You should speak to your doctor or a natural family planning consultant before using this indicator as a family planning method.


Lactational amenorrhoea methods

As we mentioned earlier, the other main type of natural family planning method is called the lactational amenorrhoea method. For the first six months after childbirth, you’re unlikely to get your periods if you fully breastfeed your baby. This is because breastfeeding can delay the return of ovulation by disrupting the release of gonadotrophin hormones.

In order for this to work as a method of reliably preventing pregnancy, the baby must be fully or nearly fully breastfeeding from you (getting at least 85% of their feeds as breast milk) and your baby must be less than 6 months old. Your doctor, health visitor or another medical professional will be able to provide advice and guidance if you plan to use this method.


How effective is natural family planning?

If family planning is followed accurately and consistently, it can be up to 99% effective at preventing pregnancy.

However, if these methods aren’t followed properly, the effectiveness drops. It takes practice and commitment to use this approach reliably.

Any decision to use a natural family planning method for contraception should be made in consultation with your doctor or a natural family planning expert.


Who is natural family planning suitable for?

This type of contraception is suitable for most women. However, certain situations can have an impact on fertility signs, so you may wish to consider an alternative method of birth control if:

  • You have a menstrual cycle that varies in terms of length
  • You have a health condition that affects your fertility signs, such as pelvic inflammatory disease or a sexually transmitted infection (STI)
  • You’ve recently come off hormonal contraception
  • You’re taking a medication that causes disruption to cervical mucus production
  • You’ve recently had an abortion or miscarriage
  • You travel across time zones on a regular basis
  • You’re a heavy drinker

You may also wish to consider alternative forms of contraception if there could be a health risk to the baby if you got pregnant. If you are unsure if natural family planning is right for you, speak to your doctor.


What are the advantages of natural family planning?

There are many advantages associated with this approach to contraception. For example:

  • You won’t experience any side effects.
  • It doesn’t involve any physical products or chemicals.
  • You can use it to plan when to get pregnant, as well as how not to.
  • It’s acceptable across all cultures and faiths.
  • Once you’ve learned the techniques involved, there’s no need for further input from health professionals.
  • It can make you more aware of typical and atypical vaginal secretions, helping you to recognise possible infections more easily.


What are the disadvantages of natural family planning?

However, there are certain potential downsides to consider too. For example:

  • If you want to have sex during your fertile window, you’ll need to use contraception, such as male or female condoms.
  • Fertility signals can be disrupted by factors such as travel, stress and illness.
  • Natural family planning doesn’t protect you from STIs.
  • It can be considerably less effective than other types of contraception if you don’t follow the methods correctly.
  • It might take you a number of menstrual cycles before you can be confident and accurate in identifying your fertile window.
  • It requires you to keep an ongoing record of your fertility indicators.
  • If you use the emergency contraceptive pill, you’ll need to wait for two full menstrual cycles before you can go back to relying on natural family planning.