In at least 30% of male infertility cases, the true cause of infertility remains unknown. The only way to evaluate male fertility was actually limited to sperm analysis, which can provide information about 3 aspects: sperm count, sperm motility and morphology. New scientific research suggests that the degree of DNA fragmentation in spermatozoa is a predicting factor for male fertility. The degree of DNA fragmentation is measured with DNA – Fragmentation Index (DFI).
Scientific research suggests that spermatozoa with a high percentage of DNA (genetic material) fragmentation are less likely to give a healthy pregnancy. A statistical analysis of hundreds of sperm samples showed that men with a DNA fragmentation percentage higher than 30% are considerably less fertile (fewer pregnancies, double miscarriages). In the past, the ‘golden standard’ for evaluating male fertility was sperm analysis. Today we know that sperm that looks normal might actually have extended DNA damage. In a study including 700 cases of in-vitro fertilisation (IVF) with ICSI (intra-cytoplasmic sperm injection) the pregnancy rate was less than 1% when DFI was more than 30%. In another study, it has been confirmed that DFI exceeding 30%should be considered as an important infertility factor. On the contrary, men with DFI less than 15% achieved pregnancy in 3 months or less. In another study including 998 fertility treatments (387 IUI, 388 IVF, 223 ICSI) it was made clear that a DFI of under 30% makes no difference between IVF and ICSI results. When DFI is over 30%, ICSI should be the method of choice: pregnancy rates are 3 times higher using ICSI compared to using IVF.
There are many factors that may explain why a man has a high DFI and therefore has fertility problems:
- Abstinence (infrequent ejaculations)
- Age (DFI rises considerably after the age of 46)
- Exposure to high levels of pollutants
- Exposure of testicles in high temperatures (e.g. professional drivers)
- Trauma of the testicles or testicular cancer
- Exposure to chemicals or radiation
- However, DFI is a relatively new test and more studies are required, so as to prove its actual value when treating male infertility.
We suggest that it is performed in the following cases:
- Recurrent implantation failure
- Past failure to fertilise
- Low embryo quality
- Recurrent miscarriage