There are times in fertility care where, despite the use of modern testing, no clear explanation is found for a couple who is struggling to conceive. This is known as unexplained infertility. 

A diagnosis of unexplained infertility does not mean that nothing is happening. Rather, it reflects the current limits of medical science. That, even with today’s advances in the world of fertility treatment, scientists are not  yet able to measure or fully understand every step involved in conception.

But importantly, it does not mean that pregnancy is not possible.

There are still many ways fertility specialists can support and guide your next steps.

Our Oxford-trained specialists at Child Fertility take time to understand your unique situation and recommend personalised care that aligns with your goals.

What is unexplained infertility?

Unexplained infertility is diagnosed when standard fertility investigations do not identify a clear cause for difficulty conceiving.

These investigations typically confirm that:

• Ovulation is occurring and that eggs are being released regularly
• The fallopian tubes are open and the uterus appears normal
• Sperm parameters are within expected ranges
• In some cases, basic hormone tests may also be used to support this overall picture.

When these key elements appear normal, but pregnancy has not occurred, the term ‘unexplained infertility’ is used. This diagnosis is not an endpoint, it is simply an acknowledgment that, at present, the cause cannot be clearly identified with the tools available.

It’s important to note that ovarian reserve testing is not used to diagnose unexplained infertility, but may be included to guide fertility planning and treatment decisions.

What causes unexplained infertility?

Unexplained infertility does not mean there is no cause. It means that, despite standard fertility tests, no clear reason has been identified using current diagnostic methods.

In many cases, fertility is influenced by a combination of subtle factors that are difficult to detect individually. These may include:

• Mild or early-stage endometriosis that is not visible on routine scans
• Subtle implantation or uterine receptivity issues
• Fertilisation challenges that occur at a microscopic level
• Age-related changes in egg or sperm quality
• Hormonal or metabolic conditions that may affect reproductive function

Because conception is a complex biological process, not all contributing factors can always be measured through standard testing. This is why a diagnosis of unexplained infertility is made only after key fertility parameters appear normal.

Why can you not get pregnant if tests are normal?

Although routine fertility tests may appear normal, several subtle influences can still affect a couple’s ability to conceive. These may include:

• Mild or undiagnosed Endometriosis, which may not always be visible on initial testing
• Subtle issues with implantation or endometrial receptivity, which are difficult to assess with routine investigations
• Sperm-egg interaction or fertilisation processes, which are not captured by standard semen analysis
• Age-related changes in egg or sperm quality, even when test results appear normal
• Underlying medical conditions, such as thyroid disorders, which may influence reproductive health

Because not every part of conception can be measured with current tests, a diagnosis of unexplained infertility may still be given, even when subtle or as-yet undetectable factors are influencing the process.

Symptoms of unexplained infertility

Unexplained infertility does not usually present with specific symptoms. Most couples only become aware that something may be affecting their fertility after trying to conceive for several months without success. The absence of clear signs can make the experience feel more uncertain, but it is also part of what defines this diagnosis.

You can also find helpful information on male and female fertility on our Male Fertility and Female Fertility pages.

Can you get pregnant with unexplained infertility?

Yes, many couples with unexplained infertility do go on to conceive. 

For some, pregnancy happens naturally over time. For others, fertility treatment may help improve the chances of conception.

Outcomes depend on several factors, including age, how long you have been trying to conceive, and your overall reproductive health.

Our specialists will carefully review your history and results before suggesting the next steps that can best support you.

When should you see a fertility specialist?

You should consider seeing a fertility specialist if you have been trying to conceive for 12 months or more without success, or sooner if you are over 35.

Early assessment can help identify whether further testing or treatment may be beneficial, even when initial results appear normal.

It may also be helpful to seek advice if:

• You are unsure about your fertility results
• You have been diagnosed with unexplained infertility and want clarity on next steps
• You would like to understand treatment options such as IVF or ovulation support
• You feel uncertain about how long to continue trying naturally

Seeking guidance early can provide reassurance, clarity, and a clearer path forward based on your individual circumstances.

Treatment options for unexplained infertility

Treatment for unexplained infertility is personalised and may vary depending on individual circumstances. Options may include:

• Trying naturally –  If there are no identified fertility issues, and particularly in younger couples, continuing to try naturally for a defined period may be appropriate. Small adjustments to lifestyle habits or optimising the timing of ovulation can support natural conception, and many couples conceive without intervention. .
• Ovulation stimulation – Medications may be used to stimulate ovulation, helping the ovaries produce eggs in a more predictable way.
• In Vitro Fertilisation (IVF) – IVF is one of the most effective treatments for unexplained infertility. It allows fertilisation to occur outside the body and can help overcome factors that are not detectable through routine testing.

Success rates for unexplained infertility

Success rates for unexplained infertility vary depending on individual factors such as age, how long you have been trying to conceive, and overall reproductive health.

Some couples may conceive naturally over time, while others may require fertility treatment to improve their chances.

In general, outcomes tend to improve when a structured treatment plan is introduced, particularly when conception has not occurred after an extended period of trying.

Treatment options such as ovulation support or IVF may help address factors that are not detectable through routine testing, improving the likelihood of pregnancy in suitable cases.

Your specialist will review your individual situation to help you understand what outcomes may be realistic for you.

Moving forward with support

A diagnosis of unexplained infertility can feel uncertain, but it also leaves room for possibility.

At Child Fertility, care is centred on clarity, discretion and individualised planning. By looking beyond standard test results and considering the full picture, our specialists help you explore the most appropriate path forward, at a pace that feels right for you.

If you have been trying to conceive and would like guidance in KSA, our team at Child Fertility is here to help. Whether you’re seeking answers, exploring possible treatment options, or simply looking for a supportive conversation, we are ready to guide you.