Sperm DNA damage has been shown to be closely associated with fertility outcomes including fertilisation, poor implantation and embryo quality as well as miscarriage and childhood disease.

The SpermComet is the next generation test now available to fertility clinics to assist in the male diagnosis.

Traditionally, diagnosis of male fertility has relied on microscopic assessment and biochemical assays to detect semen quality. These tests are essential to provide fundamental information on which to base an initial diagnosis, however these tests do not address sperm function.

The SpermComet Test explained




Testing with Semen Analysis

A semen analysis cannot distinguish between fertile and infertile men and cannot predict ART success. The SpermComet test is better as it identifies the amount of sperm DNA damage in each sperm.

Comparing DNA tests


The SpermComet® test is the next generation test for fertility health.

  • It is the ONLY test that can measure the extent of damage in individual sperm. Other tests can only detect damage in a minority of cases.
  • It can detect damage in sperm of 80% of unexplained men compared to 18% with other tests.
  • It provides most unexplained couples with a diagnosis.
  • It only takes 5000 sperm compared to 1 million sperm for other tests. This means a small sample left over from a semen analysis is enough.  Clinics don’t need to ask the man for another dedicated sample, just consent for DNA testing.
  • It is so sensitive it can predict fertilization failure and poor embryo and blastocyst quality, as well as poor pregnancy rates with IVF. Other tests can’t. They are only useful outside the lab, from pregnancy to miscarriage.

Adjacent is a chart of men attending fertility clinics who have a normal semen analysis. Sperm DNA tests are more sensitive and you can see that when their sperm are tested for sperm DNA quality, these sperm have molecular defects although they look normal on the outside.  Again, the SpermComet® is much more sensitive than other popular test.

With the SpermComet®, damage can be  picked up in 80% of men, compared to 13% with the SCSA and 15% with the TUNEL.

Taken from Simon et al, 2014

Tests for Aneuploidy and FISH

At ESHRE, Munich, July 2014, a major retrospective study of sperm from 1223 infertile men was presented. The men were assessed for aneuploidy as part of their infertility workup. The study concluded that there was no benefit in testing men who could produce an ejaculate, no matter how poor the semen quality. The only group of men with a higher prevalence of chromosomal abnormalities were those with azoospermia.

This also means that tests like fluorescence in situ hybridization (FISH) add nothing to the male workup. It can only examine a small number of chromosomes whereas DNA testing gives an overall of damage in the whole sperm genome. There is little evidence that the aneuploidy of embryos as seen in pre implantation diagnosis is directly related to the sperm rather than egg. The only cases where FISH or karyotyping may be useful are in couples who have had recurrent pregnancy loss, in men with very low sperm counts or in men recovering from cancer and chemotherapy.

MACS Testing

Magnetic Activated Cell Sorting (MACS) is a technique to isolate the best sperm for IVF. It has potential, but as yet it can only isolate sperm that we know are abnormal. It cannot isolate sperm with good DNA so it does not supersede sperm DNA testing.

Testing with other DNA tests

The Halo test was popular for a while. It was cheap and easy to incorporate into the routine lab. However, large multicentre studies have shown that Halo has no relationship with either pregnancy or live birth following IUI, IVF or ICSI.

The TUNEL has no recognised published clinical thresholds. Each group using it for research has different protocols and baseline values.

As well as only detecting sperm DNA damage in a minority of sperm (20-30%), these tests only give an  ‘all or nothing’ value for the whole population of semen. Neither the SCSA nor the TUNEL can give a measure of DNA damage in each sperm. For example, their 15% means that damage could be detected in only 15% of men and 85% of men had no detectable damage.

The SpermComet® test can quantify the DNA damage in every sperm we measure.

In other tests 15% means 15% of sperm in the sample had detectable damage and 85% has none. In the  SpermComet® 15% damage means there is an average of 15% damage in every sperm. This is why the SpermComet® is more sensitive at every early fertility check point-from fertilization, through to embryo quality, pregnancy and finally to a healthy baby.