What is the optimum age of male fertility in infertile couples?

Background: The results of studies on the effects of age on sperm parameters are controversial. The aim of this study was to evaluate the association of age and semen parameters. Methods: In this study 278 men (32.3±6.5 years, range 19 to 65 years) referred to a private medical laboratory to evaluate couple infertility were included from April 2016 to March 2017. Cases with azospermia were excluded from the current study. In some cases, the cause of the couple infertility was female factor, which is not addressed in this report. Semen samples were collected using standard methods. We analyzed semen parameters using computer-assisted sperm analysis. Results: All semen parameters were deteriorating with increasing age; however, only the correlation of age with sperm motility was statistically significant. This correlation showed a quadratic model with an increasing trend up to a peak at 32 years and then decreasing (R²=0.024, P=0.03). We divided cases into two age groups and repeated the analysis separately for patients younger than 31 years (median age of our population) or patients older than 31 years. We found that the semen parameters including count, volume, total motility and vitality showed a negative correlation with age in older patients, however, this correlation was significant only for the total motility (P=0.02). Conclusion: Age has an insignificant impact on sperm count, whereas, Sperm motility showed an increasing trend up to a peak at 32 years and then decreasing significantly.