Effect of male age on reproductive function: A comparison of young and middle-aged men

PURPOSE: There have been concerns regarding potential effects of older paternal age on male reproductive function. However, currently available data on this topic are insufficient and controversy exists. We analyzed semen characteristics and reproductive hormones in young men and middle-aged men to investigate the effect of age on male reproductive function. MATERIALS AND METHODS: This study examined healthy males of reproductive age who visited a single infertility center from January 2016 to July 2021. The young group consisted of men who were less than 35 years-old, and the middle-age group consisted of men who were more than 45 years-old. RESULTS: The two groups had no significant differences in sperm concentration ([89.9±59.4]×10(6)/mL vs. [104.4±82.1]×10(6)/mL, p=0.108) or sperm morphology (normal forms: 3.6%±1.5% vs. 3.4%±1.6%, p=0.131). However, the middle-age group had a smaller semen volume (3.2±1.5 mL vs. 2.5±1.4 mL, p<0.001), lower sperm motility (42.3%±9.8% vs. 31.2%±12.4%, p<0.001), lower progressive sperm motility (39.2%±10.3% vs. 28.4%±12.6%, p<0.001), and a higher serum follicle-stimulating hormone level. CONCLUSIONS: Our results suggest that advanced male age might have a negative effect on fertility potential, as in women. This finding has important clinical implications because more couples are choosing to have children when they are older. Further studies on this issue, especially those that examine reproductive outcome, are warranted.