The miscarriages or conception problems you’re having could be attributed to faulty sperm DNA, which is unfortunately not assessed in a routine semen analysis. Sperm DNA fragmentation testing is done to check the integrity of the genetic material of your sperm.

A simple semen analysis, although sufficient in many cases, only tells us about the count, morphology, and motility of the sperm, but gives no information about its genetic defects, which are often the cause of recurrent miscarriages.  

Infact, nearly 15% of males with normal semen analysis results actually are infertile, according to a report published in the Translational Andrology and Urology Journal (1).

Sperm DNA fragmentation testing

What is a normal sperm DNA fragmentation?

Any sperm cell will have some degree of DNA fragmentation, but the ones that have more than 30% damage are considered less suitable for good reproductive outcomes.

What does sperm DNA testing check for?

Men with a higher concentration of sperm DNA fragmentation (SDF) are likely to have fertility problems. Since faulty sperm causes imperfect embryogenesis, the conception will either not take place, or if it does, may result in a miscarriage.

An analysis of 16 studies that used different methods of testing the sperm DNA, found that there was a significant increase in miscarriage and pregnancy loss in patients with high percentage of SDF as compared with those with low DNA damage.

This exhaustive study, published in the journal Human Reproduction (2), concluded “miscarriage rates are positively correlated with sperm DNA damage levels.”

Miscarriages due to sperm DNA damage

How to check sperm DNA integrity?

A sample of semen is collected to test the amount of DNA damage. Any of the following methods may be used to check for the structural integrity of the sperm DNA:

  • Sperm chromatin structure assay (SCSA) – A chemical dye is used to stain normal sperm green and broken sperm red
  • Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay – Fluorescent enzymes are used to mark single and double strand breaks
  • Single-cell gel electrophoresis (COMET) assay – Sperm is subjected to electrophoresis and only fragmented sperm will travel through the gel
  • Sperm chromatin dispersion test (SCD) – Acid denaturation is done after which the normal sperm can be identified as they produce halos

Although their application is limited, these tests may be very useful for couples who face unexplained infertility or multiple miscarriages due to sperm damage.

Is SDF testing always required before IVF?

Sperm DNA testing is not recommended as a routine test for all infertile couples.

Reports from the American Society for Reproductive Medicine (3), the British Fertility Society (4), and the European Society for Human Reproduction and Embryology (5), have all suggested that there is not enough evidence to include sperm DNA testing as a routine clinical protocol for all infertility patients.

What causes sperm DNA fragmentation?

Internal causes

  1. Faulty recombination during spermatogenesis
  2. Protamine 1 ratio to Protamine 2 – this has to be 1:1 for the sperm to be normal
  3. Improper maturation of the spermatid
  4. Abortive Apoptosis – as the sperm cells mature, they undergo programmed cell death, called apoptosis. In some cases, this process is not completed, resulting in incomplete death and DNA fragmentation in the nucleus of the cell.
  5. Oxidative stress – Reactive oxygen species (ROS), if not countered by proper anti-oxidants, may damage the DNA of the sperm

External factors

  1. Infections – Genital and urinary infection by Chlamydia trachomatis and Mycoplasma been found to have increased incidence of SDF (6)
  2. Age – DNA damage has been found to be greater in men with age over 35 years, and it seems to increase as they get older
  3. Varicocele – Found in around 15-20% of the male population, varicocele is known to cause oxidative stress that results in sperm DNA damage. Research suggests the removal of the varicocele also improves the integrity of sperm DNA (7).
  4. Testis temperature – Any significant heat stress to the scrotum can cause DNA strands to break, studies have found (8).
  5. Reaction to medicine, vaccines – Cancer treatments like chemo and radiotherapy are known to have a harmful effect on male fertility, causing a reduction in sperm count and also damage to its DNA. Vaccines like Miloxan are also found to cause an increase in SDF but that may be reversed within a month’s period (9).
  6. Environmental factors – Research has found that air pollution may raise the risk of SDF and the same can be done by exposure to ultraviolet light, cell phone radiation and anything that causes oxidative stress (10).
  7. Smoking and alcohol – Smoking and alcohol consumption are not only deleterious for semen volume and sperm count but studies have found they can cause SDF too (11).
  8. Sperm collection and preparation for ART – Sperm collection and its washing protocol is also known to have an effect on the quality of the sperm.
  9. Sperm storage temperature – It is known that the sperm DNA is more likely to stay intact between temperatures of 5 °C and 15 °C but it may get damaged at higher temperatures

Can you get pregnant with fragmented sperm?

With the increase in DNA fragmentation over 30%, the possibility of blastulation, healthy embryos, and the chances of a successful pregnancy reduce drastically. Even if a pregnancy is carried to term, there is a high chance of birth defects in babies due to damaged sperm.

Can you fix DNA fragmented sperm?

Yes, there are several treatments to improve DNA fragmentation sperm.

Based on the sperm DNA results, your doctor will be able to recommend the required lifestyle changes and medications, and guide you towards treatments that will allow for the best chances for success.

The treatment for sperm DNA fragmentation will depend upon the cause of it. Lifestyle changes and a diet replete with anti-oxidants may be able to help improve the DNA fragmentation that is caused by free radicals.

Other treatments include:

  1. Antibiotics, if an infection is present
  2. Varicocele surgery
  3. Stopping drugs, smoking, and alcohol consumption and adopting a more active lifestyle
  4. Foods rich in vitamin C & E, and those containing anti-oxidants
  5. Surgical sperm extraction, as DNA damage in sperm is known to occur after it has left the testes

If significant amount of SDF is found in the initial testing, DNA of the sperm should be checked again after 3-4 months to see if the suggested treatments and lifestyle changes have brought about the desired improvements.

How long does it take to improve sperm DNA fragmentation?

Human sperm cycle is around 3 months. It has been shown that improved diet and lifestyle, and supplementation with anti-oxidants significantly improves DNA fragmentation in the sperm within 3 months (12).

What food reduces DNA fragmentation in sperm?

A generally healthy, protein-rich diet is considered to be good for your sperm. Men with high intakes of fresh fruits and vegetables, whole grains, eggs and fish were found to have lesser incidence of sperm DNA damage (13).

For more information and cost of Sperm DNA fragmentation testing, get in touch using the red contact button on this page.
  1. Kadioglu, A., & Ortac, M. (2017). The role of sperm DNA testing on male infertility. Translational andrology and urology6(Suppl 4), S600–S603.
  2. Lynne Robinson, Ioannis D. Gallos, Sarah J. Conner, Madhurima Rajkhowa, David Miller, Sheena Lewis, Jackson Kirkman-Brown, Arri Coomarasamy, 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,
  3. Practice Committee of American Society for Reproductive Medicine (2008). The clinical utility of sperm DNA integrity testing. Fertility and sterility, 90(5 Suppl), S178–S180.
  4. Coughlan, C., Clarke, H., Cutting, R., Saxton, J., Waite, S., Ledger, W., Li, T., & Pacey, A. A. (2015). Sperm DNA fragmentation, recurrent implantation failure and recurrent miscarriage. Asian journal of andrology17(4), 681–685.
  5. Coughlan, C., Clarke, H., Cutting, R., Saxton, J., Waite, S., Ledger, W., Li, T., & Pacey, A. A. (2015). Sperm DNA fragmentation, recurrent implantation failure and recurrent miscarriage. Asian journal of andrology17(4), 681–685.
  6. Gallegos, G., Ramos, B., Santiso, R., Goyanes, V., Gosálvez, J., & Fernández, J. L. (2008). Sperm DNA fragmentation in infertile men with genitourinary infection by Chlamydia trachomatis and Mycoplasma. Fertility and sterility90(2), 328–334.
  7. Zini, A., & Dohle, G. (2011). Are varicoceles associated with increased deoxyribonucleic acid fragmentation?. Fertility and sterility96(6), 1283–1287.
  8. Paul, C., Murray, A. A., Spears, N., & Saunders, P. T. (2008). A single, mild, transient scrotal heat stress causes DNA damage, subfertility and impairs formation of blastocysts in mice. Reproduction (Cambridge, England)136(1), 73–84.
  9. Gosálvez, J., Vázquez, J.M., Enciso, M., Fernández, J.L., Gosálbez, A., Bridle, J.R., & López‐Fernández, C. (2008). Sperm DNA Fragmentation in Rams Vaccinated with Miloxan. The Open Veterinary Science Journal, 2, 7-10.
  10. Rubes, J., Selevan, S. G., Sram, R. J., Evenson, D. P., & Perreault, S. D. (2007). GSTM1 genotype influences the susceptibility of men to sperm DNA damage associated with exposure to air pollution. Mutation research625(1-2), 20–28.
  11. Anifandis, G., Bounartzi, T., Messini, C. I., Dafopoulos, K., Sotiriou, S., & Messinis, I. E. (2014). The impact of cigarette smoking and alcohol consumption on sperm parameters and sperm DNA fragmentation (SDF) measured by Halosperm(®). Archives of gynecology and obstetrics290(4), 777–782.
  12. Nguyen, N.D., Le, M.T., Tran, N.Q.T. et al. Micronutrient supplements as antioxidants in improving sperm quality and reducing DNA fragmentation. Basic Clin. Androl. 33, 23 (2023).
  13. Vujkovic, M., de Vries, J. H., Dohle, G. R., Bonsel, G. J., Lindemans, J., Macklon, N. S., van der Spek, P. J., Steegers, E. A., & Steegers-Theunissen, R. P. (2009). Associations between dietary patterns and semen quality in men undergoing IVF/ICSI treatment. Human reproduction (Oxford, England)24(6), 1304–1312.

Reviewd by: Dr. Meenakshi, PhD

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