Computer-assisted semen analysis systems: comparison with routine evaluation and prognostic value in male fertility and assisted reproduction.

Semen analysis was performed by employing a computer-assisted semen analysis (CASA) system (SM-CMA), in comparison with visual estimation by microscope. There was a significant relationship between the values obtained by both methods, but a large range of differences in individual values was observed. Results of semen analysis in 407 men complaining of reduced fertility were investigated for their relationship to fertility outcome. The parameters obtained by the CASA system were analysed in relation to time to conception, applying the Cox proportional hazards model of regression. In univariate regression analysis, all examined CASA parameters were shown to have a significant effect on cumulative hazard function. However, applying a multivariate step forward approach, only percentage of motile spermatozoa and log-transformed values of sperm count remained significant predictors of later fertility due to the close intercorrelations among the examined covariates. We concluded that the determination of elaborate motility characteristics as obtained by CASA systems is of limited value to optimizing the evaluation of male fertility status.