Sperm DNA Fragmentation Test

The COMET test measures sperm DNA damage (fragmentation).  Sperm DNA can be damaged when sperm are made, breaking the DNA into smaller fragments. Men with high levels of sperm DNA damage are less likely to get their partner pregnant and have increased risk of miscarriage (1-5). Even if your sperm count is normal, the sperm may not be of good quality, and therefore sperm DNA damage can reduce the chance of you/partner having a baby (1-5).

Why should I get tested?

Knowing whether you have sperm DNA damage can help you make informed decisions about the type of treatment and/or lifestyle changes to improve your sperm DNA and fertility.

Can I improve my sperm DNA?

DNA damage is usually caused by oxidative stress. Oxidative stress produces free radicals which attack the DNA molecule causing breaks in the DNA strands. Sperm DNA damage is often associated with underlying medical conditions (such as varicocoele, infection or fever) or certain lifestyle choices (such as smoking or heat).

Your consultant will discuss measures you can take and the best treatment options when discussing your result.

Are there any risks?

Sperm DNA damage testing is a non-invasive procedure performed on a semen sample, usually before treatment as an additional diagnostic test. There are no significant additional risks to the patient.

There is currently no HFEA traffic light rating for sperm DNA damage testing.  It is important to note that whilst there is some evidence for a relationship between sperm DNA damage and fertility treatment outcome, some of this evidence is inconclusive. Please refer to the treatment add-ons page of the HFEA website at https://www.hfea.gov.uk/treatments/treatment-add-ons.6


Contact us

If you would like to book an appointment with one of our doctors you can:

  • Speak to the booking team on +44 (0)20 7837 2905  (Mon – Fri 8.30am – 6pm)
  • Email us on info@crgh.co.uk 
  • Visit our Appointments page, fill out the contact form and a member of the team will be in touch.



1. Robinson, L.Gallos, I.D, Conner, S.J ,  Rajkhowa, M. Miller, D. Lewis, S. Jackson Kirkman-Brown, J. and Coomarasamy A. (2012) The effect of sperm DNA fragmentation on miscarriage rates: a systematic review and meta-analysis . Human Reproduction, Volume 27, Issue 10, October 2012, Pages 2908–2917.

2. Santi, D., Spaggiari, G. and Simoni, M. (2018) Sperm DNA fragmentation index as a promising predictive tool for male infertility diagnosis and treatment management – meta-analyses. Reproductive Medicine Online. Int Braz J Urology. Volume 37, Issue 3, Pages 315–326.

3. Simon, L., Zini, A., Dyachenko, A., Ciampi, A. and Carrell D.T. (2017) A systematic review and meta-analysis to determine the effect of sperm DNA damage on in vitro fertilization and intracytoplasmic sperm injection outcome. Asian journal of andrology. Jan-Feb;19(1):80-90.

4. Vu Bach, P. and Schlegel, P.N. (2016) Sperm DNA damage and its role in IVF and ICSI. Basic and Clinical Andrology 26:15.

5. Chen Q, Zhao J, Xue X, Zhu G. The association between sperm DNA fragmentation and reproductive outcomes following intrauterine insemination, a meta analysis. Reprod Toxicol 2019; 86:50-55.

6. https://www.hfea.gov.uk/treatments/treatment-add-ons.

IVF Packages With Access Fertility

IVF Packages With Access Fertility
CRGH is partnering with Access Fertility to offer a series of IVF programmes and packages. For more information please click below.

Newsletter Sign Up

Upcoming Events

No event found!