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Fertility and causes of infertility

Fertility is the ability to get pregnant. Fertility can be affected by several factors, including lifestyle, health and age.

In this section


The time it takes to get pregnant can vary. Most women get pregnant within a year of trying (age can makes a difference here), with around 1 in 3 getting pregnant within a month of trying. Around 1 in 7 couples in the have difficulties getting pregnant.

Are you ready to conceive? Use our tool to find out.

What is fertility?

Fertility is about the ability to get pregnant. More than 8 out of 10 couples where the woman is aged under 40 will get pregnant within one year if they have regular unprotected sex. More than 9 out of 10 couples will get pregnant within 2 years.

Regular, unprotected sex means having sex every 2 to 3 days without using contraception.

You don't need to time having sex only around ovulation. Having vaginal sexual intercourse every 2 to 3 days will give you the best chance of getting pregnant.

Remember it’s important for you and your partner to try and keep sex enjoyable by concentrating on each other and your relationship, rather than worrying about conceiving. This will help you limit stress.

Find out more about how long it can take to get pregnant. 

Contraception and getting pregnant

Most women use contraception as a safe way to avoid getting pregnant when they are not ready for children. When you stop contraception, it is often because you would like to try for a baby. You can read more about stopping contraception here.

If you have been taking contraception that uses hormones (such as the Pill, the patch, injections) for a long time, you may not know your cycle very well (for example how long it is). This is because the bleed that happens when you move to a new packet of the Pill is not a true period. A true period happens when you ovulate (release an egg from your ovaries) and the Pill prevents ovulation. Read more about how pregnancy works.

If you’ve stopped taking contraceptives that were based on hormones your periods may be a bit irregular (come at different times of the month) for the first few months while your body gets used to the change in hormone levels. Read more about stopping contraception

The Pill does not cause infertility but it may cover up conditions that are linked to infertility because lack of periods is a sign of ovulation problems, endometriosis or PCOS. If you do not have periods anyway, these problems may be missed until you come off contraception.

Lifestyle and fertility

Your fertility is affected by your lifestyle. These are the top lifestyle tips for improving your fertility:

When to get help with fertility

Infertility is only usually found out when a couple haven't managed to get pregnant. Make an appointment with your GP if you haven’t conceived after a year.

You should see your GP sooner if:

Your GP will ask you about your lifestyle, general health and medical history. They may ask you questions about:

  • any previous pregnancies or children you may have
  • how long you have been trying to conceive
  • how often you have sex
  • how long it has been since you stopped using contraception
  • if you take any medication
  • your lifestyle and habits.

They may also advise you about the things you can do to improve your chances of getting pregnant and how your partner can improve their fertility.

Causes for infertility or reduced fertility

What is unexplained infertility?

Unexplained fertility is when no reason has been found for a person’s fertility problems. In this case you should not be offered any fertility drugs taken by mouth as this does not improve the chances of conceiving naturally. Unexplained fertility is more likely if you are over 36 than if you are under.

If you have been trying to conceive naturally for more than two years (including the year before your fertility tests) you may be offered IVF

All about fertility tests

If you and your partner have been trying unsuccessfully to get pregnant, you will both be offered fertility tests.

Tests for men

Men should be offered a semen test to measure the quantity and quality of their sperm.

Tests for women

Fertility tests for women may include:

  • blood tests to check your hormone levels
  • tests (including blood tests) to see how well your ovaries may respond to fertility drugs
  • an examination to see whether your fallopian tubes are blocked.

Fertility treatment

This will depend on what’s causing the problems and what’s available in your local area.

There are three main types of fertility treatment:

Read more about treatment for infertility


The Fertility Network UK has support and forums for those affected by infertility.

1. NICE (2013) Fertility problems: assessment and treatment NICE guideline, National Institute for Health and Care Excellence

2. Gnoth et al. (2003) Time to pregnancy: result of the German prospective study and impact on the management of infertility. Human Reproduction 2003 Sep;18(9):1959-66.

3. NHS Choices (accessed 01/05/2018 Infertility Page last reviewed: 14/02/2017 Next review due: 14/02/2020

Review dates

Last reviewed: 29 June 2018
Next review: 29 June 2021