What is DFI?

DNA fragmentation index (DFI) defines the chromatin integrity (DNA) in spermatozoa. It aids in detection of the percentage of sperms with DNA fragmentation in a semen sample. With sperm DFI testing, our best IVF doctors in Delhi are able to evaluate the extent of male fertility in relation to fertilization and the formation of good-grade embryos for implantation. Sperm Chromatin Dispersion (SCD) test is one of the methods to determine DFI. This assay is one of the fastest as well as commonly used tests for calculating DFI. SCD aids in reduced IVF treatment cost compared to other available DFI testing assays.

Spermatozoa plays a vital role in embryonic development. Any abnormal embryogenesis causing implantation failure can be looked over by assay through assessment of DNA integrity linked with the quality of spermatozoa. Sperm DFI is a better biomarker in anticipating high success rate of assisted reproduction and diagnosis of reason supporting male fertility.

Sperms under microscope showing fragmented (small/no halos) and normal spermatozoa (large/medium halos)
Fig: Sperms under microscope showing fragmented (small/no halos) and normal spermatozoa (large/medium halos)

Causes of Sperm DNA fragmentation

There are various factors that cause fragmentation in sperm DNA, which are either extrinsic or intrinsic.

Extrinsic factors: This includes external factors such as Lifestyle (obesity, alcohol, and smoking), Radiations, Varicocele, Chemical toxins, Ageing (advance age), Genital Tract Infections.

Intrinsic factors: These are biological factors, including Oxidative stress, Structural defect in DNA, Apoptosis before maturation of sperm, Genetic mutation.

Why Sperm DNA fragmentation is important?

How is DFI detected?IVF specialists mostly prefer the Sperm Chromatin Dispersion test. It is best known as the Halo test and the most commonly used test for assessing DFI. In this test sperms with low or no DNA damage form medium or large Halo around the sperm head as depicted in the figure below. While those sperms with high DNA damage make no halo or small halo around the sperm head. Taking into account the entire pool, DFI is generated.