Objective: To investigate the effects of different proportions of cryoprotectant to seminal plasma on the motility of post-thaw human sperm.
Methods: Different proportions of cryoprotectant to seminal plasma (1:1 and 1:3) were used for freezing sperm, and the forward movement and total motility rates of the frozen-thawed sperm were compared.
Results: The forward movement and total motility rates were (58.60 +/- 5.57)% and (66.17 +/- 5.24)% before cryopreservation. The 1:1 proportion achieved post-thaw forward movement and total motility rates of (40.53 +/- 8.97)% and (51.23 +/- 9. 30)%, while the 1:3 (44.7 +/- 8.67)% and (51.50 +/- 7.40)%, respectively. Significantly decreased sperm motility was observed after cryopreservation (P < 0.05). Statistically significant differences were found in the forward movement but not in the total motility of the frozen-thawed sperm between the two proportions.
Conclusion: Cryopreservation causes obvious damage to human sperm. Higher proportion of cryoprotectant to seminal plasma (1:3) can improve the forward movement of post-thaw sperm as compared with the lower one (1:1).