Comparative Study between Slow Conventional Freezing and Cryoprotectant-Free Vitrification of Human Spermatozoa in Large Volume

Abstract

Background: Cryopreservation is the collection, freezing, and long term storage of sperm, and is a highly effective method of protecting male fertility. Cryopreservation of semen has been widely used as a vital method for fertility preservation of male patients before undergoing chemotherapy, radiotherapy, and/or surgery that may lead to testicular failure or ejaculatory dysfunction. Objective: The aim of this study was to compare the aseptic technology of cryoprotectant-free vitrification of human spermatozoa in large volume, to conventional freezing protocol as regards post thawing motility, vitality and sperm DNA fragmentation. Patients and methods: This study included a total of 20 male patients seeking seminal fluid analysis, attending at the andrology laboratory of a specialized IVF center (ADAM International Hospital for Fertility and Sterility, Giza, Egypt. Patients were presented with the diagnoses of normozoospermia, oligozoospermia (either isolated or combined with asthenozoospermia or teratozoospermia). Results: Motility of (in a large volume (300 µl) in the absence of permeable cryoprotectants displayed significant statistically lower levels as compared to conventional Sperm Freezing. It was shown in different groups at different times (post thawing and 1-hour and 24-hour) of assessment that motility of vitrified spermatozoa decreases in comparison with slow conventional freezing as we go from the baseline. DNA fragmentation of vitrified spermatozoa showed higher levels as compared to conventional slow freezing but there is no significant statistical difference between vitrification and conventional slow freezing in DNA fragmentation. Conclusion: It could be concluded that vitrification technique was quite far away from comparison with slow conventional freezing protocol, and still need for further modifications and wide scale of study to achieve the good results.