Effect of H
treatment on human frozen-thawed sperm motility in each suspension. Total frozen-thawed sperm suspensions (n = 21) were divided into 2 groups, those with higher (forward motility ≥ 50%, normozoospermic, n = 6) or lower (<50%, asthenozoospermic, n = 15) motility. Sperm motility was determined before and after treatment with sperm-wash medium containing 50%, 75% and 100% of H2 for 30 min. Data represent means ± SD. *P < 0.05, versus the untreated sperm suspension (a). Comparison of forward motility before and after treatment of each sperm suspension with higher (b) or lower (c) motility. P-values were determined using paired t-test.