Comparative study of seminal parameters between samples collected in 1992 and samples collected in 2010

Objective: The aim of this study was to conduct a comparative study of semen quality in two large populations; one evaluated in 1992 and another in 2010, in order to evaluate any possible decline in male fertility due, at least in part, to environmental factors. Material and Methods: A total of 701 subjects in 1992 (TOTAL group 1992) and a total of 626 subjects in 2010 (TOTAL group 2010) were enrolled in our Andrology Unit. Each group was subdivided into 3 subgroups: Subfertile, Pathology and Control. Standard semen analysis was performed using the Superimposed Image Analysis System, according to WHO guidelines 1987 (for TOTAL group 1992) and WHO guidelines 1999 (for TOTAL group 2010). Results: The mean values of sperm number (concentration/ml as well as the total ejaculate) and progressive motility were significantly higher in TOTAL group 2010 than TOTAL group 1992. Atypical forms in TOTAL group 1992 semen samples were significantly lower than TOTAL group 2010. The mean age of TOTAL Group 2010 was significantly higher compared with TOTAL Group 1992. In particular, the mean age gap was more evident in Subfertile subjects. Conclusions: In conclusion, environmental factors have not determined a significant decline in seminal parameters in the past 18 years.