Unexplained Subfertility


Woman in tears

Like most Fertility Specialist, we faced patients with all kinds of fertility problems everyday. One of the most unique group of patients would be those who are categorised as unexplained subfertility.


It is the most frustrating & awful diagnosis for the patients. These patients are generally well but frustrated. The label of unexplained subfertility is a diagnosis of exclusion, which means that these patients had gone through most of the tests for subfertility and all the tests came back with normal results, but yet they are not able to get pregnant naturally.


In general, up to 10-25% of couples will not find any causes for their subfertility after going through fertility testing. This diagnosis can be frustrating as many of them would wonder: why is it they have not achieved a pregnancy given that all the test results had been normal?


The important thing to note is that even though all the tests are normal, it does not mean that there are no factors that prohibit them from having a baby naturally.


It is important to note that most of the fertility tests are mainly simple fertility tests. These tests do not necessarily assess function.


For example, despite showing both of your Fallopian tubes are patent through a dye test (hysterosalpingography, HSG) or a diagnostic laparoscopy, it does not necessary translate that the Fallopian tubes function are good and it does not necessarily ensure normal transport of eggs and sperm in the Fallopian tubes as there has not been a valid test for this. We know that Fallopian tubes were lined with multiple fine hairs (cilia) within the tubes, and the function of these fine hairs is to transport the eggs and sperms to meet at the most suitable place to encourage fertilisation. The cells in the Fallopian tubes also produce secretions to encourage the process of fertilization. Although the Fallopian tubes were patent, if these functions of the Fallopian tubes were poor, fertilization fails to occur. Unfortunately, there are still no tests for these conditions.


There are also conditions whereby there are poor quality of eggs or poor functionality of the sperms which attributes to this diagnosis. As Fertility Specialists, we can visualized the number of eggs you have and measure the hormones which governs egg productions. However, there is no valid test to check the quality of the eggs until the day one goes through an IVF (in-vitro Fertilization) where the doctors and the embryologists would be able to examine the eggs under microscope. Therefore, apart from being a treatment, IVF can be a diagnostic tool in its own right.


The same principle applies to the functionality of the sperms. During semen analysis, we can see the number, the activity, speed and shapes of the sperms. However, there is no test to check whether the sperms can fertilize eggs until the day we perform an IVF using these sperms. Again, IVF becomes a diagnostic test in this scenario.


If you had been diagnosed with unexplained subfertility, my advice to you would be not to leave it for ‘nature to take its course’. There maybe other underlying conditions whereby the current fertility tests available are unable to address the issues or to diagnosed the condition. It is important to put things into perspective and move on with Fertility Treatment.





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