Infertility affects 15% of couples of reproductive age with male infertility contributing to 40% of all cases. As a result of population ageing and adverse changes in lifestyle, infertility continues to increase but with only marginal improvement in pregnancy and birth rates after assisted reproduction treatment in the developed world. In the last 30 years, assisted reproduction treatment has become increasingly utilized, with the number of cycles increasing by 8-9% per year in Europe. Still, pregnancy and live-birth rates remain disappointingly low (average 27–33%: HFEA, 2012). One reason for this is that little has been done to resolve the causes and potential therapies for male infertility at the molecular level. Furthermore, there are currently no routine pharmaceutical therapies for male infertility.

Conventional semen analysis continues to be the only routine test to diagnose male fertility even though it is known that such descriptive assessments cannot discriminate between the sperm of fertile and infertile men (reviewed by Lewis et al 2013). The shifting values for normality (all ‘normal’ values are now lower) in the fifth edition of the WHO manual (World Health Organization, 2010) compared with the previous WHO editions may result in even less men being classified as infertile.

Given the limitations of semen analysis, sperm DNA tests are becoming popular additions to the male work up. After all, sperm DNA is the code of life – the only element which influences pregnancy and the birth of a healthy child. Neither sperm count, motility nor morphology matter after fertilization. DNA tests go beyond the simple semen analysis to explore the sperm at a molecular level.

Unlike semen analysis parameters, there is now a plethora of studies indicating that sperm DNA damage is a major contributor to male infertility as well as poor outcomes following assisted reproduction treatment, including impaired embryo development, miscarriage and birth defects in offspring (Simon et al, 2016).

The SpermComet is the only sperm DNA test that measures the amount of damage in individual sperm. This makes it more sensitive. For example the SpermComet detects sperm DNA damage in 80% of couples with idiopathic infertility compared to only 18% with the SCSA test (The SpermComet test explained).

As with any molecular test, these tests need to be outsourced to dedicated labs with specially trained staff. The process is very simple.

The SpermComet test can be requested directly through our laboratory in Belfast. Samples will be collected at your clinic and shipped to us for testing. Results will be returned within seven days of arriving at our labs. Alternatively, patients can get the test via the Pathlab, London.

Interpretation of results

SpermComet DNA test – your results and what they mean

If the sperm DNA damage is high, the clinic can consider this information along with that of test results from the woman to optimize clinical management and provide bespoke treatment for each individual couple. It may be decided ICSI is a better choice than IVF as ICSI may give the egg a better chance of repairing sperm DNA damage


There are very few cases of male infertility that can actually be cured. Generally fertility treatment focuses on women with techniques that enable us to circumvent the man’s problem. That’s why it is so important to test the man carefully so that the best treatment may be chosen first time around. If a couple present with infertility but the man’s semen appears normal following a semen analysis, the routine approach is to offer the couple IVF when ICSI may be more successful for them. 


A recent large study from the UK  (Smith et al (2015)) has shown that with each repeated cycle of IVF there is less success. Even after 5 cycles over 5 years, less than 70% of couples have live births.

Many clinics suggest that anecdotally couples with idiopathic infertility have poorer success rates following IVF. For this group of ~25% of couples presenting at our clinics, more accurate tests are therefore needed to diagnose the couple’s problem, in order to decide whether IVF or ICSI will be more successful for them.