Unexplained infertility: Definition, diagnosis and treatment

18th January, 2022 • 6 min read

In the UK, 1 in 7 couples has problems trying to get pregnant (conceive). And a quarter of those couples won’t find a reason for not getting pregnant, as everything is normal or appears to be normal. This is known as unexplained infertility.

Read on to learn how unexplained infertility is diagnosed, and what to do if you’re finding it hard to get pregnant for no obvious reason.

What is unexplained infertility?


can be a confusing description that raises more questions than answers. However, what it means is that, after having medical checks and tests, no cause can be found as to why you haven’t been able to get pregnant.

How is unexplained infertility diagnosed?

About 84% of couples will get pregnant without medical help in less than a year, if they’re having regular (every 2 or 3 days) unprotected sex.
A doctor can investigate if nothing has happened after a year of trying – or after 6 months if you’re a female aged 35 or over, or if you have a medical condition that could affect your fertility.
Your doctor will ask you about:

  • your medical and sexual health – including any previous births or
    if you’re female
  • the methods of birth control (
    ) you’ve been using
    your age, weight and lifestyle – including any smoking, drinking and recreational drug use

They may also want to do some checks and tests. You might feel embarrassed, or find the tests intrusive, but they can help your doctor find any possible problems. At this stage, you might want to consider counselling. Talk to your doctor, or get in touch with health charities to see what help they offer.

Find useful information on other areas of infertility with our

complete Guide

Fertility tests for females can include:

  • examining your pelvis for signs of infection, lumps or pain
  • blood tests to see if you’re
    and to check for other health conditions (depending on your symptoms)
  • tests for
    sexually transmitted infections
    , such as
  • an
    ultrasound scan
    to check your ovaries (where your eggs are made), womb (uterus) and fallopian tubes (in which eggs travel from your ovaries to womb)

Fertility tests for males can include:

  • checking your testicles and penis to look for lumps and other problems
  • chlamydia testing
  • semen analysis, to look for any problems with your sperm

Further tests: fertility X-rays and surgery

In some cases, your doctor will need to refer you to a specialist NHS infertility clinic for further tests.

  • If you’re female, you may have a special X-ray of your womb and fallopian tubes called a hysterosalpingogram.
  • You may also need a surgical procedure to see if there are any physical causes of infertility that haven’t been picked up by tests or scans. If you’re female, this will usually be a
    , where a small cut is made in your lower tummy so a camera can be inserted to show images of your womb, fallopian tubes and ovaries. This can look for fallopian tube problems and signs of conditions such as
    , which can cause fertility problems.

If all the tests come back normal, this could be classified as unexplained infertility.

What are the possible causes of unexplained infertility?

Being told you have unexplained infertility means there’s no identifiable reason for your inability to get pregnant. You may be ovulating, and you may be healthy and fit. Unfortunately, doctors can’t always pinpoint exactly why some people are infertile.

Read about the common

causes of infertility in females
causes of infertility in males

What can I do if I’ve been diagnosed with unexplained infertility?

The word ‘rollercoaster’ is often used to describe the experience of people living with unexplained infertility. You may be feeling frustrated, anxious and confused.

However, it doesn’t always mean you’ll never have children, or that you won’t have a natural pregnancy after an unexplained infertility diagnosis.
There are medical options to help you conceive, and support and advice is available, whatever your situation.
You can find support from various associations, including these in the UK:

How to treat unexplained infertility

Talking to your doctor is the best place to begin if you’d like to consider infertility treatment. The main options are:


Your doctor may prescribe a medicine, such as clomifene or tamoxifen, which helps stimulate the ovaries to release eggs.

Assisted conception

Your doctor may suggest you try assisted conception. This involves either fertilising an egg outside of your womb, or via a tube into your womb. It can include:

  • in vitro fertilisation (
    ) – when 1 or more of your eggs are removed from your ovaries, fertilised with sperm in a lab, and placed into your womb to develop
  • artificial insemination, or intrauterine insemination (IUI) – when sperm is inserted into your womb through a thin tube that’s passed through the neck of your womb (cervix)
  • donations – egg or sperm donations are usually carried out via IVF

Read more about

infertility treatment

When to speak to a doctor about unexplained infertility

You should see a doctor after a year of trying to get pregnant, or earlier if you’re female and 35 or older, or have any

risk factors
or worries.
It’s important that you and your partner go together. It’s OK if you feel nervous, embarrassed or emotional – your doctor will be able to advise and support you, and they know that this can be a stressful situation.
If you’re diagnosed with unexplained infertility, your doctor will also be able to advise you about your options.
Infertility treatment can be physically and emotionally draining, and isn’t guaranteed to work. Some people decide they’d rather not try treatment – and that’s OK. If you decide not to have treatment or it doesn’t work, you may want to ask your doctor about counselling, or look for other forms of support.
In the UK, you can find information and support from the associations mentioned above.
You may also want to look into other options, such as adoption or surrogacy. See
Adoption UK
Surrogacy UK
for more information.

Key takeaways

  • 1 in 7 couples in the UK have problems getting pregnant
  • there are various medical tests that can check for things that might be affecting your fertility – but sometimes no cause is found
  • a quarter of people with fertility problems will be told they have unexplained infertility
  • unexplained infertility doesn’t mean you can’t ever have children
  • treatment options include medicines and assisted conception procedures

Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.