Capacity of objectively assessed sperm motility characteristics in differentiating between semen of fertile and subfertile men.

A simple and inexpensive computer-assisted method for the objective assessment of sperm motility characteristics was employed to evaluate semen samples of 42 fertile men and 70 subfertile patients. The capacity of each motility parameter to discriminate between semen of the two groups was evaluated by receiver operating characteristic curve analysis. Velocity, linear velocity, and "angular" velocity are reasonably accurate, whereas linearity and angularity index had a very poor discriminating power. The best discrimination between the two groups was the proportion and concentration of sperm with rapid linear progressive motility, based on the cut-off value of linear velocity greater than or equal to 22 microns/sec. This parameter was 90% accurate in discriminating semen of infertile men from that of subfertile patients.