Infertility is when a couple cannot get pregnant (conceive), despite having regular unprotected sex.

Around one in seven couples may have difficulty conceiving. This is approximately 3.5 million people in the UK.

About 84% of couples will conceive naturally within one year if they have regular unprotected sex.

For every 100 couples trying to conceive naturally:

• 84 will conceive within one year
• 92 will conceive within two years 
• 93 will conceive within three years

For couples who have been trying to conceive for more than three years without success, the likelihood of pregnancy occurring within the next year is 25% or less.

Deciding to seek help

Some women get pregnant quickly, but for others it can take longer. It is a good idea for a couple to visit their GP if they have not conceived after one year of trying.

Women aged 36 and over, and anyone who is already aware they may have fertility problems, should see their GP sooner. The GP can check for common causes of fertility problems, and suggest treatments that could help.

A couple will only be diagnosed as being infertile if they have not managed to have a baby after one year of trying. There are two types of infertility:

• primary infertility – where someone who has never conceived a child in the past has difficulty conceiving
• secondary infertility – where a person has had one or more pregnancies in the past, but is having difficulty conceiving again

Read more information about how infertility is diagnosed.

What causes infertility?

There are many potential causes of infertility, and fertility problems can affect either the man or the woman. However, it is not always possible to identify the cause.

Common causes of infertility in women include lack of regular ovulation (the monthly release of an egg), blockage of the fallopian tubes and endometriosis. However, for 25% of couples, the cause is unexplained. In men, the most common cause is poor quality of semen (the fluid containing sperm that is ejaculated during sex).

For some people, leading a healthy lifestyle and staying up to date with regular health checks and tests may help to prevent infertility.

What treatment is available?

Types of fertility treatment available include:

• medical treatment for lack of regular ovulation
• surgical procedures – such as treatment for endometriosis
• assisted conception – which may be intrauterine insemination (IUI) or in-vitro fertilisation (IVF)

The treatment offered will depend on what is causing your fertility problems and what is available from your local CCG.

You may wish to consider private treatment. This can be expensive, and there is no guarantee it will be successful.

It is important to choose a private clinic carefully. You can ask your GP for advice, and you should make sure you choose a clinic that is licensed by the Human Fertilisation and Embryology Authority (HFEA).

Read more about how infertility is treated.

Some types of infertility treatment can cause complications, including:

• side effects of medication
• increased risk of ectopic pregnancy
• multiple pregnancy
• stress

Read more about complications associated with infertility treatments.