Sperm DNA Fragmentation is used to investigate male infertility as well as to investigate repeated failed IVF attempts, preterm births, and miscarriages.
The genetic integrity of the spermatozoon is essential for the normal development of the fetus. The high level of DNA fragmentation in sperm cells can be a cause of male infertility that conventional tests - sperm concentration, motility analysis, morphology assessment - can not detect. The results of scientific studies show that regardless of the assisted reproduction technology used, the high level of sperm DNA fragmentation significantly reduces the chance of a successful pregnancy.
- A high level of sperm DNA fragmentation does not appear to affect fertilization or early mitoses
- In contrast, a high level of sperm DNA fragmentation can affect initial divisions and blastocyst formation if the paternal genome (DNA) is switched on
- DNA fragmentation levels are closely linked to abortion rates after IUI, IVF, and ICSI as well as pregnancy rates
- DNA fragmentation is significantly higher in infertile men
- Men with poor semen parameters are more likely to have a high degree of DNA fragmentation
- High levels of sperm DNA fragmentation may also be found in men with normal semen parameters
Benefits of Sperm DNA Fragmentation testing
The test provides a reliable analysis of the integrity of sperm DNA, which can help identify men who are at risk of not starting and developing a healthy pregnancy properly. Information on sperm DNA integrity can assist in the clinical diagnosis, and treatment of male infertility and can be of significant prognostic value in evaluating the results of assisted reproduction.
High rates of Sperm DNA Fragmentation and pregnancy
Normally, healthy pregnancies also occur in couples where the partner has a high percentage of sperm with fragmented DNA, although the chances are greatly reduced when the percentage of sperm with fragmented DNA is higher. Embryos derived from sperm whose DNA is highly fragmented have a poor prognosis. Younger oocytes can provide protection against a high degree of DNA fragmentation by repairing DNA from defective spermatozoa, much more effectively than older oocytes. Thus, a couple seeking assisted reproduction therapy, in which sperm DNA has a high level of fragmentation, has a better prognosis if the partner is young in age.
Causes of Sperm DNA Fragmentation
An important causative factor for sperm DNA damage is oxidative stress. Other factors include abnormalities in the regulation of apoptosis or impairments in the activity of the enzyme topoisomerase. Increased sperm DNA fragmentation may be related to:
- Sperm cytoplasmic droplets
- Diseases with fever
- High testicular temperature
- Drugs of abuse
- Exposure to environmental and occupational pollutants
- Advanced age
Which patients can benefit from the test?
Patients who can be helped by testing DNA fragmentation and subsequent targeted therapeutic interventions are patients with:
- Unexplained infertility
- Abnormal Sperm Analysis
- Advanced age
- Exposure to harmful substances
- Pregnancy history of a partner with an underdeveloped fetus
- Pregnancy history of a partner with a problematic blastocyst development
- Partner's history with multiple failed IVF / ICSI
- Repeated miscarriages of the partner
Some of the causes of DNA fragmentation cannot be treated. But if the damage is caused by reactive oxygen species, then a lifestyle change and a diet properly designed to protect against oxidative stress can help reduce DNA fragmentation levels. Treating possible infections with antibiotics could also reduce DNA fragmentation. There is some evidence that surgical treatment of varicocele can improve the integrity of spermatozoa DNA. The reduction in fragmentation levels can be assessed by repeating the test three months after the first test. Studies show that DNA damage occurs mainly after sperm leave the testicles. In addition, ICSI has been shown to be a more effective IVF treatment than conventional IVF in men with a high degree of DNA fragmentation.
The results of sperm DNA fragmentation refer to 3 statistical categories of potential fertility:
- DFI <15%: excellent fertility potential
- DFI 15 to 30%: good fertility potential
- DFI> 30%: low to moderate fertility potential
DFI: DNA Fragmentation Index, Percentage of spermatozoa containing damaged DNA
A statistically significant DFI limit for infertility of more than 30% has been established.
A normal pregnancy with a high DFI is possible, but the higher the level of fragmentation, the greater the chance of premature birth and miscarriage.