Determination of the percentage of sperm with fragmented genetic material (Sperm DNA Fragmentation – SDF Index)

Infertility is an important scientific and social issue throughout Europe. Recent, efforts focus on a better investigation of problems related to male infertility. A semen analysis of sperm motility and morphology are the main tests for the evaluation of a man’s fertility. However, with simple semen analysis, it is impossible to consider parameters such as the quality of the genetic material of the sperm.

Published scientific research states that the genetic material of the sperm is “programmed” to undergo many changes during maturation. These changes allow valuable DNA information to transfer dynamically and unchanged to the egg. Simultaneously it makes the sperm vulnerable to mistakes – critical for both its fertilisation capacity and the viability of the resulting embryo.

This data led to the need for a more comprehensive evaluation of the sperm and the implementation of more specific tests, which determine the rate of DNA fragmentation of sperm (DFI). The studies conducted until now have shown that the “mistakes” in the condensation of the DNA-packaging process are sufficient to result in multiple “fractures” in the chain of the genetic material.
The results gathered confirm that sperm samples with an increased percentage of sperm with fragmented genetic material are directly related to:

• a low rate of fertilisation in IVF attempts,
• a low quality of embryos,
• failure of embryo implantation in the uterus,
• high percentage of miscarriages, either after IVF or after spontaneous conception

For reproduction specialists, it is clear that a “normal” sperm sample does not necessarily mean that it is capable of fertilisation, which probably explains many cases of hitherto unexplained infertility.

The phenomenon of DNA fragmentation in sperm has led to intense research interest in recent years in order to determine the limit affecting male fertility adversely. From current data, it appears that fragmentation exceeding 30% is directly related to infertility. In such cases, although the egg has corrective mechanisms, it does not seem to be enough for the creation of embryos with a normal genetic make-up.

Extensive research shows that fragmentation of genetic material is caused by different pathological factors such as varicoceles and various infections of the reproductive system, but also by factors of modern life, such as exposure to chemicals and toxins, smoking – active and passive, even eating habits. Some of the most important changes that can be made to reduce the problem are:
1) stop smoking
2) limit alcohol consumption
3) stop eating food with chemical preservatives
4) eat meals including vegetables and fruits that are rich in antioxidants.

In addition, vitamins C, E and others seem to improve DNA structure in sperm and thus the pregnancy rate. In cases of very high rate of fragmentation, taking sperm directly from the testis, where the percentage of fragmentation smaller, gives very positive results.

Research into sperm and the parameters affecting fertilisation capacity is progressing very rapidly. Data already revealed is changing the way male infertility is treated.

Identifying the problem, combined with special antioxidant treatment, can significantly improve success rates for attempts at reproduction. Simple semen analysis should now be combined with more specialised tests in order to complete the examination.


  • Embryolab is one of the few IVF units in the world to have a Department of Genetic Counselling within the Unit.
  • Medical Examination performed at the Unit by specialised cytogeneticists.
  • The accuracy of the results is controlled through participation in an external quality control scheme (UKNEQAS)