Infertility is when a couple cannot get pregnant (conceive) despite having regular unprotected sex. Around 1 in 7 couples may have difficulty conceiving. About 84% of couples will conceive naturally within a year if they have regular unprotected sex (every 2 or 3 days). For couples who have been trying to conceive for more than 3 years without success, the likelihood of getting pregnant naturally within the next year is 1 in 4, or less.

Getting help

Some people get pregnant quickly, but for others it can take longer. It's a good idea to see a GP if you have not conceived after a year of trying. Women aged 36 and over, and anyone who's already aware they may have fertility problems, should see their GP sooner. They can check for common causes of fertility problems and suggest treatments that could help. Infertility is usually only diagnosed when a couple have not managed to conceive after a year of trying.

There are 2 types of infertility:

primary infertility – where someone who's never conceived a child in the past has difficulty conceiving

secondary infertility – where someone has had 1 or more pregnancies in the past, but is having difficulty conceiving again

Causes

Infertility can be caused by many different things. For 1 in 4 couples, a cause cannot be identified.

Infertility in women

Infertility is commonly caused by problems with ovulation (the monthly release of an egg from the ovaries).

Some problems stop an egg being released at all, while others prevent an egg being released during some cycles but not others.

Scarring from surgery

Pelvic surgery can damage and scar the fallopian tubes, which link the ovaries to the womb. Cervical surgery can also sometimes cause scarring or shorten the neck of the womb (the cervix).

Cervical mucus problems

When you're ovulating, mucus in your cervix becomes thinner so sperm can swim through it more easily. If there's a problem with the mucus, it can make it harder to conceive.

Fibroids

Non-cancerous growths called fibroids in or around the womb can affect fertility. In some cases, they may prevent a fertilised egg attaching itself in the womb, or they may block a fallopian tube.

Endometriosis

Endometriosis is a condition where small pieces of the womb lining (the endometrium) start growing in other places, such as the ovaries. This can damage the ovaries or fallopian tubes and cause fertility problems.

Pelvic inflammatory disease

Pelvic inflammatory disease (PID) is an infection of the upper female genital tract, which includes the womb, fallopian tubes and ovaries.

It's often caused by a sexually transmitted infection (STI). PID can damage and scar the fallopian tubes, making it virtually impossible for an egg to travel down into the womb.

Sterilisation

Some women choose to be sterilised if they do not want to have any more children. Sterilisation involves blocking the fallopian tubes to make it impossible for an egg to travel to the womb. It's rarely reversible – if you do have a sterilisation reversed, you will not necessarily be able to have a child.