You went through the tests. Both of you. And the results came back… normal. Or at least, nothing obviously wrong. And yet here you are, still not pregnant, wondering why on earth medicine can examine almost every system in the human body but cannot tell you why conception isn’t happening.
If that is where you are right now, you are not imagining it. This experience has a clinical name — unexplained infertility — and it affects more couples than most people realise.
The Clinical Definition
Unexplained infertility is diagnosed when:
- A couple has been trying to conceive for 12 months or more (or 6 months if the woman is 35 or older)
- Standard fertility investigations for both partners show normal results
- No identifiable cause for the failure to conceive has been found
The standard investigations that must be completed before this diagnosis is made include: ovulation confirmation, uterine and tubal assessment, and semen analysis. If any of these have not been done, a diagnosis of unexplained infertility is premature.
What the Tests Are — and What They Miss
Standard fertility testing is genuinely good at finding obvious problems. It will identify blocked tubes, absent ovulation, severe male factor, and anatomical abnormalities in the uterus. What it cannot assess:
- How chromosomally normal your eggs are (this can only be assessed during IVF with genetic testing)
- Sperm DNA fragmentation — standard semen analysis checks count, motility, and shape, but not DNA integrity
- Endometrial receptivity — whether the uterine lining is ready to accept an embryo at the right moment
- The moment of fertilisation — whether sperm and egg are actually interacting correctly
This is why unexplained infertility is called a “diagnosis of exclusion.” It is not the end of the investigation — in some cases, IVF itself becomes the next diagnostic step.
| ‘Normal test results don’t mean your fertility is the same as someone with no infertility history. They mean the standard tests haven’t found the cause yet.’ |
Why This Diagnosis Is So Emotionally Difficult
Many couples find unexplained infertility harder to cope with than a named diagnosis. When there is a name — PCOS, low sperm count, blocked tubes — there is a target. There is something to treat. With unexplained infertility, there is no clear enemy. And without a clear enemy, it is easy to turn inward: to wonder if you’re stressed enough, eating wrong, exercising too much, not enough.
The frustration is not a sign of weakness. It is a natural response to uncertainty in one of the most significant areas of your life. For more on managing the emotional impact, read: ‘The Emotional Impact of Unexplained Infertility’ [link to Article 5].
What Unexplained Infertility Does NOT Mean
- It does not mean you will never conceive naturally. Some couples do.
- It does not mean treatment will not work. Many couples with this diagnosis respond very well to IUI or IVF.
- It does not mean the tests were wrong. It means they found no explanation within the scope of what they measure.
- It does not mean you should stop investigating. Additional testing (sperm DNA fragmentation, ERA, hysteroscopy) may uncover factors a standard workup missed.
Is Unexplained Infertility Common in South Africa?
Yes. Globally, unexplained infertility accounts for approximately 15–30% of all infertility presentations (Fertility and Sterility, 2020). In South African private fertility clinics — where testing is thorough — it is a commonly encountered diagnosis. For international couples travelling to Cape Town for treatment, South Africa’s leading units use internationally accredited protocols, meaning your workup here is likely to be comprehensive.
What Happens Next?
After a diagnosis of unexplained infertility, you have several options. The right one depends on your age, how long you have been trying, your ovarian reserve, and your clinical picture. The main paths:
- Expectant management — continuing to try naturally, sometimes for a defined period
- IUI with ovarian stimulation — a relatively low-cost, low-intervention option often tried first
- IVF — higher per-cycle success rates and also offers diagnostic insights not available from standard testing
For a full comparison, read: ‘IUI vs IVF for Unexplained Infertility — Which Should You Choose?’ [link to Article 3]
For a complete overview of this diagnosis, tests, and options, see: ‘Unexplained Infertility: A Complete Guide’ Click Here
| KEY TAKEAWAYS |
| ✓ Unexplained infertility means all standard fertility tests are normal — not that nothing is wrong. |
| ✓ Important fertility factors (egg quality, sperm DNA, implantation) are invisible to standard tests. |
| ✓ The diagnosis is common — affecting 15–30% of couples presenting with infertility globally. |
| ✓ Treatment works for many couples with this diagnosis. Your options are real and evidence-based. |
| ✓ Additional testing may uncover factors a standard workup missed — ask your RE about sperm DNA fragmentation and ERA. |
References
- Fertility and Sterility (2020). Should couples with unexplained infertility have IUI or IVF?
- ESHRE (2023). Evidence-based guideline: unexplained infertility.
