Time series analysis of sperm concentration in fertile men in Toulouse, France between 1977 and 1992

Objectives-To investigate whether sperm production has changed during the past 16 years in the Toulouse area of France. Design-Time series analysis of sperm donors' specimens between 1977 and 1992. Setting-Sperm bank of university hospital in Toulouse, France. Subjects-302 healthy fertile men candidate sperm donors more than 20 and up to 45 years old and without any infertile brothers. Main outcome measure-Spermatozoa concentration. Results-Donors' mean age at time of donation was 34.05 (SD 5.13), but this increased significantly (P<0.001) during the study, from 32.4 in 1977 to 36 in 1992. Mean sperm count of samples was 83.12 x 10(6)/ml (SD 68.42 x 10(6)/ml). Sperm concentration was positively linked to the year of donation (Pearson's coefficient r = 0.12, P < 0.05), but this correlation disappeared after adjustment for age of donors (r = 0.09, P > 0.05). Conclusion-Sperm concentration has not changed with time in the Toulouse area.