Natural Contraception

How does it work?

 

Fertility awareness involves noting signs of fertility during your menstrual cycle to calculate when you are most likely to become pregnant.

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This can include:

• Measuring your body temperature

• The length of your menstrual cycle

• Cervical mucus

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Temperature

Oestrogen and progesterone can cause changes in your body temperature during your menstrual cycle.

After ovulation, your temperature is slightly higher.

You should measure your temperature with a digital thermometer every morning when you get out of bed.

It should be done at the same time everyday and before you eat or drink anything.

The fertile period is likely over if you have 3 readings in a row which are slightly higher than the previous readings.

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Cervical Mucus

Your cervical mucus changes in quantity and texture during your menstrual cycle due to hormonal changes.

Cervical mucus can be checked by inserting a clean finger into your vagina or inspecting your underwear.

Shortly after your period, there will be no mucus and the vagina will be dry.

At the start of the fertile period, a sticky and cloudy white mucus is produced.

Just before ovulation the mucus becomes clear and wet and becomes thicker again after ovulation.

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Menstrual cycle

This method involves recording the first day of your period on a calendar and calculating the number of days between each period to find out your cycle length.

The menstrual cycle lasts 28 days on average but can last between 21 and 40 days.

Measure your cycle lengths for at least 1 year (12 months) to ensure an accurate calculation. Subtract 20 days from your shortest cycle to calculate the first fertile day.

The fertile period usually lasts around 8-9 days.

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Who can use it?

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Fertility awareness can be used by the majority of women.

 

However, it may not be suitable if you:

• Have irregular periods

• Are unwell

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How effective is it?

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Fertility awareness can be up to 99% effective if used perfectly and depending on the method used. In reality, it is around 76% effective with typical use.

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Advantages

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There are advantages to using fertility awareness such as:

 

• Increased awareness of your fertility

• There are usually no medical side effects

• There is little to no cost involved

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Disadvantages

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The disadvantages of fertility awareness include:

 

• Planning and organisation is needed

• It can take a while to learn how to use this method

• Sex must be avoided or other contraception used during the fertile period

• Lack of protection against STIs and HIV