Is your infertility “unexplained”?

“I almost wish I had something wrong that I could fix – if everything’s ok why can’t I get pregnant?”



Professor Charles Kingsland explains …


“Every diagnosis of infertility can be hard to deal with – but when all the usual blood tests are normal, and every scan, sample and examination reveals nothing remarkable – we are left with unexplained infertility. I know my patients find this incredibly frustrating and difficult to deal with”

One study of unexplained infertility of less than two years duration showed that 50% of couples with unexplained infertility would conceive over the next two years, and suggested that the right treatment was to do nothing. The problem is that the other 50% could wait for two years and still not become pregnant. Reproduction in humans is annoyingly inefficient and not many patients are willing to wait for years and do nothing.

Infertility might be described as “unexplained” if the woman is ovulating regularly, her fallopian tubes are ok, there is no sign of endometriosis, adhesions or growths and if the man has a normal sperm count. If the couple are having intercourse at least twice a week around the time of ovulation but there is still no conception after two years then a diagnosis of unexplained infertility may be appropriate. Studies vary as to the number of patients who are handed this news which is why it is important to ensure that patients are very carefully investigated and managed. Investigations should include a vaginal ultrasound scan to check for any abnormality in the womb ovary or tubes, blood tests to check that an egg is being released and a semen analysis.

If one or both of you smoke, are overweight or have medical condition that is not well controlled then although the fertility tests may all be normal, trying for a pregnancy will not be successful. With a thorough review of your personal and medical history, a fertility specialist may be able to identify something that needs to be changed in order to help.

Some women may release eggs before they are mature, or their eggs are chromosomally abnormal – especially relevant if the woman is older or is experiencing a premature menopause. Further testing is indicated if a problem with egg quality or quantity is suspected. Usually an FSH blood test will have been done by the GP, so further assessment with an ultrasound scan and an antral follicle count or a blood test such as AMH (Anti Mullerian hormone) may reveal more information.

Whilst a simple semen analysis may show that there is plenty of moving, normal looking sperm it doesn’t reveal whether the sperm are healthy. An additional test called a Sperm DNA Damage test may lead to an understanding of why a pregnancy hasn’t been achieved yet and treatment is available to help.

What all the tests can’t tell us is whether the sperm is fertilising the egg, and unfortunately this can only be assessed during IVF treatment itself. However if this is the case then there are treatments available that can solve this issue.


There are many reasons for infertility and those mentioned above are some of the most common. If you have been trying for a family and its taking too long the best advice is to seek help early. At CARE we see many patients who do not have a clear reason why they have not become pregnant – but their treatment can be successful even if infertility remains unexplained.


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