Background: Nowadays, cryopreservation of human sperm is considered as a common technique for treating infertility. Although cryopreservation causes a decrease in sperm motility and viability in infertile men, the effect of freezing the sperm by vitrification in infertile men has not been evaluated. The aim of this study was to evaluate the effect of vitrification on some parameters of sperm including motility, morphology, viability, count and apoptosis after thawing in infertile men.

 Materials and Methods: Semen samples (No=17) of participants referring to Clinical Center for Infertility of Yazd were collected by masturbation. Semen analysis was performed according to WHO standards. The smears provided were fixed for TUNEL staining. Some samples directly cryopreserved by cryoloope method and stored for at least 7 days. After thawing, samples were evaluated for sperm parameters. Data obtained before and after the vitrification were compared using paired t-test and Willcaxon statistical tests.

Results: A significant decrease in viability and morphology of the sperm and an increase in the rate of apoptosis were observed after vitrification. The percent of apoptosis was negatively correlated with normal parameters of spermatozoa (especially progressive motility and viability). Conclusion: The results indicate that vitrification has a detrimental effect on sperm parameters and apoptosis rate in infertile men. However, the rate of apoptosis in this method was lower than that in other freezing methods.