Couples or individuals usually receive an infertility diagnosis if they have unsuccessfully tried to get pregnant for a year or more. At this stage, people will undergo a series of standard tests to try and determine the cause of infertility.

When all these tests come up negative and there is no apparent cause for infertility, doctors refer to these as cases of “unexplained infertility.” This may feel like a vague umbrella term, ironically leaving a lot of things unexplained.

Do these people have less of a chance of getting pregnant than those with explained infertility? What does “unexplained infertility” actually mean?

Fertility testing and diagnosis

According to the World Health Organization, infertility is a disease associated with the reproductive system that is defined by a failure to become pregnant naturally after a period of 12 months or more of regular unprotected sex. If the female partner is 35 or older, infertility testing should be considered after 6 months instead of 12.

Infertility affects between 8-12% of couples worldwide, with 40-50% of these cases being due to causes associated with male infertility. Meaning male infertility is an equally important cause of infertility as women-related causes.

In order to better understand what is causing infertility, and determine the best course of treatment there are a series of tests performed by doctors. First, in order to rule out any obvious causes, the doctor will perform a physical exam and discuss sexual history with both partners.

Next, the doctor will try to narrow down the causes by focusing on the most obvious causes of infertility. While further testing may be necessary later, starting with the least invasive approach is best.

Male infertility tests

The easiest way to determine male infertility is by performing semen analysis. Semen analysis is a noninvasive procedure in which a man provides a semen sample for testing and will measure the following factors to look for abnormalities:

• Low sperm count
• Low semen volume (<1.5ml)
• Sperm vitality
• Sperm morphology or movement
• Cells in the ejaculate

Hormone analysis is also generally done along with semen analysis. The two most important hormones associated with healthy semen production are follicle-stimulating hormone (FSH) and testosterone (T).

If there are any abnormalities found in either the semen or hormone analyses, doctors may perform additional tests to explain exactly what the issue is. If men are unable to produce semen at all or produce very little, genetic testing or more invasive surgical testing may be performed to determine the reason.

Female infertility testing

While an initial physical exam may point doctors in a more specific direction, there are a series of general tests doctors use to help understand the cause of infertility.

• Ovarian reserve tests: in order to determine a woman’s egg reserve. This number is considered critical when it falls below 27,000 and generally occurs when a woman is around 35years old.
• Uterus testing: ultrasounds, sonohysterograms, hysterosalpingograms (HSG), and hysteroscopies are types of uterus tests that can be used to understand if fibroids, polyps, scarring, or tumors, are preventing a woman from getting or staying pregnant.
• Fallopian tube tests: HSG, x-ray, and blood tests can be used to make sure that the fallopian tubes are not blocked in any way.
• Hormone tests: blood tests can help determine levels of follicle-stimulating hormones, estrogen, and anti-mullerian hormones.

If nothing abnormal is found in these general tests, more invasive surgical procedures, such as laparoscopy, can be used to surgically examine a woman’s reproductive organs to try and find the cause of infertility.

What is “unexplained infertility?”

If all of the standard infertility tests are performed and no clear explanation can be found, a woman or couple will receive an unexplained infertility diagnosis, which is also known as idiopathic infertility.

30% of couples worldwide are diagnosed with unexplained or idiopathic infertility, making it one of the biggest causes of infertility.

This diagnosis has been challenged by some fertility doctors, arguing that just because someone cannot find the cause of infertility, does not mean that there is no cause. Knowing there is a problem, but not knowing the cause can be extremely frustrating for those experiencing “unexplained infertility.”

However, it is important to remember that an “unexplained infertility” diagnosis does not mean you will never conceive. Sometimes the issue will self-correct over time. In fact, the rate of spontaneous conception is much higher in these cases than in cases of defined causes of infertility, reaching up to 80% in younger couples.

While this is not always the cause, a better understanding of the issue might also be of comfort to those suffering from “unexplained infertility.”

What causes “unexplained infertility?”

Asking what causes “unexplained infertility,” may seem like an oxymoronic question. However, misdiagnosis is often an issue. For example, fertile couples who have failed to conceive within a year may receive a misdiagnosis.

Another common cause of misdiagnosis is when fertility tests yield inaccurate results due to issues with the testing process. These issues are not always because of the doctors administering the tests, but because the results are sometimes so minor, that the abnormalities are almost impossible to detect.

Another issue with “unexplained infertility,” is that the clinical tests looking for obvious causes of infertility fail to account for several conditions such as age-related infertility in women. This means women over the age of 35 are twice as likely to be diagnosed with “unexplained infertility.”

While women over a certain age may need a different course of treatment than other people experiencing infertility, the distinction between young women with “undiagnosed infertility” and those with age-related “undiagnosed infertility” must be made.

In other words, women over the age of 35 are more likely to experience difficulty getting pregnant than younger women, but because there is currently no specific test currently available to measure egg quality, they will be lumped into the “unexplained infertility” diagnosis.

Other things that could warrant an “unexplained fertility” diagnosis are the following:

• Poor egg quality
• Poor sperm quality
• Ovulation issues
• Not enough intercourse at the right time
• Problems with reproductive organs that were not detected in infertility tests

Treatment options for “unexplained infertility”

Because by definition, those diagnosed with “unexplained infertility,” do not have one clear issue to address, meaning treatment options will try to account for the most common causes. The most common treatment options for “unexplained infertility” are as follows:

• Timed intercourse: This is usually the first treatment option for “unexplained infertility,” and involves timing extra sexual intercourse during the time a woman is ovulating. In women under the age of 35, timed intercourse increased the chances of conceiving were between 14-23%.
• Intrauterine insemination (IUI): This procedure is usually accompanied by ovulation-inducing medication. This procedure involves “washing” the sperm and inseminating it directly into the uterus, at the time an egg is released, with the hope of fertilization. Success rates vary and are around 7-25% per cycle, depending on whether or not IUI is paired with fertility medication.
• Clomid: The choice fertility medication used for ovarian stimulation, often paired with IUI. Clomid prevents estrogen from binding to cells, which causes changes to the pituitary gland, causing the release of an egg. There is a 3% clinical pregnancy rate with Clomid.
• Injectable gonadotropins: This is a medication that contains hormones and stimulates egg production in women and can also treat low sperm count in men. Like Clomid, this drug is often combined with IUI for maximum results. Clinical pregnancies resulted in 35% of patients using this drug.
• Lifestyle changes: in addition to the other treatment options for “unexplained infertility,” those diagnosed should make sure they are living as healthy a lifestyle as possible. This means avoiding the consumption of tobacco and alcohol, exercising, and eating healthy. They should also avoid unnecessary stress, if possible.
• IVF treatments: If the other treatment options for “unexplained infertility” have been unsuccessful, IVF is often recommended. One study found that 6% of women with “unexplained infertility” who used IVF had success getting pregnant. While IVF has very good outcomes, this option is the most expensive.

Because “unexplained infertility” is such an ambiguous diagnosis, those that receive it may be worried about the chances of them successfully conceiving. However, this is a common misconception.

Depending on the cause, some people with “unexplained infertility” might actually have a higher chance of having a child.

Those with “unexplained infertility” should try and fully understand the cause of their diagnosis in order to understand the best possible course of treatment in order to increase their chances of a successful outcome.