Male age is more critical to sperm DNA integrity than routine semen parameters in Chinese infertile males

This retrospective study evaluated the correlation between the sperm DNA integrity results and infertile male age or sperm motility in 654 infertile men undergoing infertility evaluations from 2013 to 2016. The correlation between the results of sperm DNA integrity and male age was positive, while a negative correlation was detected between sperm DNA integrity and sperm motility in all subjects. According to age (≤30, 30–35 and ≥35), men with normozoospermia or abnormal semen parameters were, respectively, divided into groups 1, 2 and 3, or groups A, B and C. The sperm DNA fragmentation index (DFI) and DFI abnormality rates in groups 3 and C were highest among their respective cohorts. But they were not significantly different between groups within the same age range. Statistically significant differences were found in male age, progressive motility, as well as total motility between patients with normal DFIs and those with abnormal DFIs in group C, but not in group 3. Older (≥35 years) infertile men have increased sperm DNA fragmentation, independent of conventional semen parameters. Male age is more critical to sperm DNA integrity than routine semen parameters.