Impact of Age and Fertility Status on the Consistency of Repeat Measurements of Sperm DNA Damage: A Single-center, Prospective, Dual Visit Study.

OBJECTIVE

To examine the relationship between abnormal routine semen parameters and DNA damage associated with advanced paternal age and infertility by controlling for common biases contested in the current literature.

MATERIALS & METHODS: Prospective study using 151 semen samples collected from men aged 18-80 at 2 visits with 1-3 months intervals. Samples were collected from both infertile and general population controls. Conventional semen parameters were measured including volume, concentration and motility. Sperm DNA damage was measured using the %DNA Fragmentation Index (%DFI) and High DNA stainability (%HDS) using Sperm Chromatin Structure Assay (SCSA). Patients were then classified according to %DFI as normal (<18), intermediate (18-27), or high (>27).

RESULTS

Significant correlation between all sperm parameters was seen between both visits regardless of age. DFI had the highest correlation between both visits (R = 0.77). Progressive motility, total motility and %DFI were significantly affected in men ≥50 years old when compared to men <35 and men 35-49 years old (P <.001). Forty-eight percent of men with intermediate %DFI changed category on their second visit, whereas men with high and low %DFI changed category in 15% and 9%, respectively.

CONCLUSION

Sperm and SCSA parameters do not change significantly between 2 visits at 1-3 months intervals in the total population and after subgrouping. Men of advanced age have poorer sperm parameters and more DNA damage. Men with initially normal or elevated %DFI are unlikely to change DNA damage category. Older men are more likely to have sperm parameters and DNA damage vary on repeat semen analysis compared to younger men.