The percentage of immotile sperm (i.e., not moving at all), the percentage of sperm showing non-progressive motility (sperm moving their tails but not moving forward, or swimming slowly but in a curve) and the percentage showing progressive motility (sperm swimming quickly forward in a straight line) were recorded. Sperm movement characteristics - straight-line velocity (VSL), curvilinear velocity (VCL), average path velocity (VAP) - were also analyzed by CASA. According to their general velocity, spermatozoa were classified as slow (50 μm/sec). The amplitude of lateral head displacement (ALH) and beat-cross frequency (BCF) were also analyzed. A minimum of three fields and 500 sperm tracks were examined at 10x for each sample chamber (image acquisition rate 25 frames/s).