Preliminary Results of a New Method of Vitrification of Spermatozoa

Sperm vitrification appears as alternative method for improving conventional freezing. New sperm vitrification studies have evaluated the ability of sucrose to protect against damage sperm physicochemical produced by freezing. Therefore, we developed and evaluated a new method of vitrification, using a combination of 0,25 M trehalose-sucrose (V) and compared the results using a conventional methods for sperm cryopreservation(CC). A prospective non-randomized study to compared the efficacy of spermatozoa vitrification protocol respect to the conventional freezing protocol. The sperm vitrification solution was 0,25 M trehalose-sucrose and plunge in liquid nitrogen directly in microdroplets of 10-20μl. A total of 25 semen samples were vitrified using the new method (V) and 25 samples were frozen by the conventional method containing glycerol (CC). The survival rates and sperm mobility rates were calculated before and after cryopreservation. Statistical analysis was performed using ANOVA test and Chi square, p<0.02 were considered statistically significant. The survival rate was significantly higher when spermatozoa were vitrified with 0,25 M trehalose-sucrose, compared with the survival using the conventional method of freezing, V = 77,60% (CI95%73,30-81,90) vs CC= 40,84% (CI95% 33,77-47.92).The progressive motility parameters were significantly higher respect the conventional freezing (V = 76,56% ± 10,34 vs CC = 47,86 ± 12,77). (P< 0,02). The sperm vitality before and after vitrification was (88.92 ± 6.24 vs 75.76 ± 7.8) respectively. Our preliminary results show that this new vitrification method can improve survival after warning sperm. A study designed to assess the fertilizing capacity of sperm in ICSI and embryo quality is being evaluated to compare the two methods of sperm cryopreservation in parallel.