What is Sperm DNA fragmentation for infertility?
DNA fragmentation in the sperms is breaking of genetic strands resulting in discontinuity. It is important that the genetic material in sperm is normal and intact for normal fertilization and successful implantation and pregnancy. For some reason, if the DNA in the sperm is fragmented then it leads to infertility and failure in IVF treatment. It can occur spontaneously and if such fragmentation accumulates it causes infertility. There seems to be a threshold level of DNA fragmentation beyond which it leads to infertility in men.
Men with low levels of fragmentation usually have normal semen parameters; whereas high levels of fragmentation is associated with abnormal semen parameters and infertility. Moreover, 8% on infertile men show abnormal DNA integrity despite normal despite normal semen parameters.
Etiology of sperm fragmentation
It may be multi-factorial. It may be due to
- Intrinsic Factors e.g. Potamine deficiency, Mutations that effect DNA compaction, a.nd advanced paternal age
- Extrinsic Factors e.g. Radiation, chemical pollutants etc.
What is The Most Common Test for Sperm DNA Fragmentation?
The most common test the clinicians perform is the DFI test. The sperm chromatin structure assay (SCSA) is the most common clinical test used to determine a DFI score although other tests such as the Comet assay, Tunel assay and acridine orange test are also used sometimes.
Why is Sperm DNA Fragmentation treatment Important?
This sperm DNA test does not provide any information about the genetic makeup of the sperm, which is essential for normal embryo development. But the high percentage of DNA fragmentation in sperm cells leads to male infertility, which the usual semen analysis cannot predict.
Men with low motility defects often have high levels of sperm DNA fragmentation in India. The degree of DNA fragmentation in sperm cells can predict outcomes for IVF-ICSI.
What is DNA Fragmentation Index?
It is the main unit of measurement of the DNA Fragmentation Index (DFI). A DFI of 30% or more significantly reduces the success rates after IVF.
The clinical index is a DNA fragmentation index (DFI) of 30%- that means 30% of the sperm have damage and 70% have no detectable damage. Couples with >30% damage are more likely to benefited with ICSI than IVF. This test should be done with patients with low motility sperms and it helps in the decision to go for IVF or IVF-ICSI