DNA Fragmentation Index(DFI) – Measures and Treatment

Synopsis

DNA fragmentation index is an important tool for the assessment of male fertility. Read below to find out more about need to assess DFI, techniques used and treatment.

DNA Fragmentation Index (DFI) is considered an important tool for the assessment of male fertility. Sperm DNA fragmentation (SDF) denotes the presence of abnormal genetic material due to breaks in the DNA strand within the sperm. SDF also occurs when the body is unable to repair breaks in the DNA. Presence of fragmented DNA in the sperm has been shown to affect male fertility potential and development of the embryo. It can also be a cause for IVF failure and recurrent miscarriages. High DFI is generally seen in men with advanced age, inflammation of the external genitals and varicocele, unhealthy lifestyle habits such as smoking and alcohol consumption, and environmental radiation and pollution.

Why do we need to assess DFI?

At present, evaluation and diagnosis of the sub-fertile male mainly encompasses traditional semen analysis, which includes the volume, concentration, vitality and morphology of the sperms. However, roughly 15% of men who have a normal semen analysis are still unable to conceive. This indicates that semen analysis alone cannot be relied upon to provide information for the assessment of male fertility, and it reflects only partially the fertilization potential of the sperm. The Sperm DNA Fragmentation index (DFI) is a measure of the damage to the DNA, the genetic material of the sperm. Thus, it is a crucial tool for detecting potential sperm damage and evaluating semen quality. DFI of more than 30% is associated with adverse effects on male fertility.

In addition to diagnosing male infertility, it is an invaluable tool in predicting the outcome of IVF, especially in couples with unexplained infertility, recurrent IVF failures and recurrent miscarriages, thereby saving valuable time for infertile couples during treatment.

Techniques to measure DFI

Main SDF detection methods include
• Sperm chromatin structure assay (SCSA)
• Sperm chromatin diffusion method (SCD)
• Comet assay (CA)
• Terminal deoxyuridine nick end labeling (TUNEL)

Out of all these techniques, SCSA is the most commonly used and reliable technique. It requires a minimum sperm count of approximately 1 million/ml.

Who should undergo DFI testing?

• Unexplained infertility
• Couples with history of poor or arrested embryonic development
• Multiple failed ART cycles
• Recurrent miscarriage
• Advanced male age
• Varicocele
• Abnormal semen analysis
• Exposure to harmful substances, tobacco, alcohol, radiation etc.

Treatment

In couples battling with infertility, if the male partner has elevated levels of SDF, especially more than 30%, rectification can be tried through lifestyle modification, significant reduction in smoking and alcohol consumption, antioxidant treatment, and ensuring a suitable period of abstinence. Underlying diseases like varicocele or infections also need to be addressed in such patients. ICSI preferred over IVF for better chances of successful fertilization. Other methods, such as sperm selection by micro-manipulation or testicular sperm extraction, can be used to select healthy sperm with nuclear DNA integrity.