Unexplained infertility – how do we fix it if we don’t know what’s wrong?

In the lead-up to a diagnosis of unexplained infertility, you may have experienced a rollercoaster of emotions: anxiety as you underwent each fertility test and waited for the results, relief when the test results came back normal, followed quickly by frustration and disappointment at being no closer to understanding why you’re struggling to conceive.

Now that you have the diagnosis, you may be left feeling confused, or even worried, about what unexplained infertility means for your chances of having a baby. If we don’t know exactly what’s wrong, how can we fix the problem and give you the best chance of having the family you long for?

Unexplained infertility explained

A diagnosis of unexplained infertility is made when a woman or couple has been unsuccessfully trying for a baby for 12 months or more and all common causes of infertility in both partners have been ruled out. While it’s not clear how many Australians experience unexplained infertility, it is estimated to affect somewhere between 8 and 28% of infertile couples worldwide.1

Unexplained infertility is a diagnosis of exclusion. This means it can only be given once all conventional fertility tests have returned normal results. For the female partner, these tests may include hormone levels and other examinations to check how her ovaries are functioning and to exclude disorders such as polycystic ovarian syndrome. Scans or other procedures to check for problems in the uterus (womb) or blockages in the fallopian tubes may also be recommended. In addition, keyhole surgery to diagnose endometriosis may be performed.

To investigate causes of male infertility, semen analysis to look at the number, motility, size and shape of sperm is usually carried out. Examinations, scans or other tests to look for problems with the testicles or the ducts through which sperm travels (blockages, for example) may be recommended. A fertility specialist may also check for hormonal imbalances or infections that may affect the male partner’s fertility.

If genetic problems are suspected, tests such as karyotype testing (a blood test) may be performed for one or both partners.

Women and couples will usually go through a comprehensive testing process before they are diagnosed with unexplained infertility. However, a fertility specialist may sometimes decide that performing certain tests carries more potential risks than benefits. In these cases, even though all available tests have not been carried out, a diagnosis of unexplained infertility is still possible.

Does unexplained infertility mean nothing is wrong?

A lot has to happen in order to make a baby; it is a complex process in which there is quite a lot of room for error. Both eggs and sperm must be healthy and physically able to meet (that is, the fallopian tubes and sperm-carrying ducts mustn’t be blocked). The sperm must be able to enter the egg to fertilise it, and the fertilised egg must implant into the lining of the uterus and develop into an embryo. Even in people without any fertility problems, the chance of achieving pregnancy each month is nowhere near 100% – rather, it’s between 15 and 25%. This goes to show that getting pregnant is no simple feat. Further, the complexity of what’s involved means that we simply cannot test for every potential problem that can occur.

It’s important for you to know that a diagnosis of unexplained infertility does not mean ‘nothing’s wrong’. Rather, it means that no currently available test can pinpoint the specific cause of your struggle. In other words, what you’re going through is real, we just can’t determine exactly what’s causing it.

So, if it’s not possible to find out what’s wrong, how can we fix it? Here’s the great news: even though we don’t know the exact cause of the problem, there are still treatments that can increase your chances of having a baby.

Unexplained infertility treatment

Below we explain the most common treatments offered to couples struggling with unexplained fertility. Because a woman’s ability to conceive naturally declines with age, women in their late 30s or 40s may be advised to commence in vitro fertilisation (IVF) without trying any other treatments.

Expectant management

In some cases, simply getting support and guidance to continue to try to conceive naturally may be sufficient. This can be done while working to improve your health if necessary. For example, losing excess weight, quitting smoking, and reducing alcohol consumption may be appropriate goals to work towards. This is known as expectant management, and for some people, it is enough to lead to a pregnancy. It is also the most cost-effective option, so if a woman is young and has a good ovarian reserve (that is, a good number of eggs left), it may represent the most appropriate treatment. More active treatments may be recommended for older women.

Intrauterine insemination (IUI)

In this procedure, washed, concentrated sperm from the male partner (or a donor) is injected directly into the uterus. This ensures that a very large number of the highest quality sperm from the sample is injected, increasing the chances of the egg and sperm meeting. IUI is useful in unexplained infertility because it sidesteps any potential problems that may prevent the sperm from entering the uterus naturally. In many cases, IUI is combined with low dose ovulation induction so that two eggs are released at a time instead of one, to further increase the chances of fertilisation.

IUI is a relatively inexpensive intervention that is often used before IVF is considered. It has a pregnancy rate per cycle of between 8 and 15%. However, the benefit is smaller for older women, with a pregnancy rate of 5% in women over 40. As a result, IVF is more likely to be recommended for this age group.

Tubal flushing

Tubal flushing is used to assess blockages in the fallopian tubes. However, it does appear to increase pregnancy rates and thus, may also be used as a dedicated fertility treatment.

In this procedure, a tube is placed through the woman’s cervix, and a water or oil-based solution is flushed into the uterus. The solution then travels through the fallopian tubes, ‘flushing’ them out. When tubal flushing is used on its own, you will be advised to try to conceive naturally in the months following the procedure. However, tubal flushing can also be performed in preparation for IUI. This ensures that no blockages prevent the egg from travelling to the uterus to meet with the injected sperm.

IVF

IVF bypasses many potential problems related to the fertilisation process by starting the process outside the womb. In IVF, a number of the female partner’s eggs (or donor eggs) are mixed with sperm in a laboratory dish.

There are two ways this mixing process may be carried out. In standard insemination, the ‘fittest’ of the thousands of sperm in a sample will fertilise the egg, as would occur in a natural pregnancy. If sperm abnormalities are suspected, or sperm count is low, intracytoplasmic sperm injection (ICSI) may be performed. This is where the best sperm is chosen and injected directly into the egg.

Once the fertilised eggs have developed into embryos in a special incubator, one of the healthiest embryos will be transferred into the uterus. In ten days, a blood test is performed to check for pregnancy.

For every 100 IVF treatment cycles that are started, 18 babies are born.2 However, IVF success rates vary according to factors such as the woman’s age. Your fertility specialist can advise you on the chances of pregnancy in your case.

Where to next?

If you are ready to explore your options for having a baby, make an appointment with a Newlife IVF fertility specialist by calling (03) 8080 8933 or by booking online. We will assess your specific circumstances and help you make a decision about the best path forward. Our specialist counsellors are also available to help you manage the unsettling emotions that can accompany a diagnosis of unexplained infertility.


  1. Gelbaya TA, Potdar N, Jeve YB, Nardo LG. Definition and epidemiology of unexplained infertility. Obstet Gynecol Surv. 2014;69(2):109‐115. doi:10.1097/OGX.0000000000000043 ↩︎
  2. Australian & New Zealand Assisted Reproduction Database (ANZARD). Assisted Reproductive Technology in Australia & New Zealand 2017 (report). Available at https://npesu.unsw.edu.au. Last accessed 16 June 2020. ↩︎