Varicocele is often associated with infertility and reduction in sperm quality, and it is one of the most common causes of reversible male infertility.
The exact mechanism of infertility caused due to varicocele formation remains unclear. One of the suggested theories is related to increased oxidative stress that causes sperm DNA damage, including DNA fragmentation, and is correlated with the decreased capacity of spermatozoa to fertilize oocytes during normal fertilization and assisted reproduction techniques. This is supported by the evidence that there is a higher prevalence of DNA fragmentation in varicocele patients and a correlation between the presence of varicocele and impaired sperm DNA integrity.
Several tests have been developed to better assess the fertility potential of sperm, including those designed to measure sperm deoxyribonucleic acid (DNA) fragmentation (SDF). The sperm DNA fragmentation index (DFI) is a potential parameter for fertility investigation, reflecting sperm DNA integrity and damage.