Effect of Trolox addition to cryopreservation media on human sperm motility

Background: Sperm parameters and motion kinetics are affected by cryopreservation. Objective: The main purpose of the current study was to determine the effect of different concentrations of Trolox as an antioxidant to freezing-thawing procedure on human sperm kinematic parameter. Materials and Methods: Semen was collected from 20 normal donors and divided into five aliquots prior to cryopreservation. The first aliquot was analyzed by computer-assisted sperm analysis (CASA). Other aliquots were mixed with cryo-protective agent containing 0, 20, 40, and 80 µmol Trolox and treated samples were cryopreserved in liquid nitrogen. After two weeks samples were thawed and sperm motion kinematics was measured by CASA. Percent motility (Mot), curvilinear velocity (VCL), straight-line velocity (VSL), average path velocity (VAP), linearity (LIN), and amplitude of lateral head displacement (ALH) were compared before and after freeze. Results: Addition of 40µmol Trolox resulted in significantly higher (p<0.05) post thaw VCL, VSL and VAP compared to other groups. Therefore the percentage of post thaw motile spermatozoa were significantly higher (p<0.01). Conclusion: The supplementation of Trolox significantly improved the post-thawed human semen quality, especially progressive motility and average path velocity.