Male aging as a causative factor of detrimental changes in human conventional semen parameters and sperm DNA integrity.

The effect of male aging on fertility potential is controversial and difficult to predict. The aim of our study was to determine the associations between age, basic semen parameters, and sperm DNA fragmentation (SDF). Comparison of four age-dependent groups (men ≤29 years, 30-35 years, 36-40 years, and >40 years) revealed a significant fall in the basic semen characteristics and sperm genomic integrity with age.

Relationship between sperm morphology and sperm DNA dispersion.

Background: The pathogenesis of teratozoospermia (<4% morphologically normal sperm cells) and the relationship between sperm morphological abnormalities and abnormal sperm nuclear DNA fragmentation, which are considered indicators of male fertility, have not been elucidated. Our research was designed to determine the prevalence of different sperm DNA fragmentation (SDF) levels in men with teratozoospermia and to establish a discriminating threshold value for SDF in assessing sperm morphology.

Methods: Basic semen characteristics and detailed sperm morphological analysis (head, neck, midpiece, and tail defects and excess residual cytoplasm) (WHO, 2010), and the nuclear sperm DNA dispersion test were performed on semen samples obtained from 523 men with teratozoospermia (n=296) and those without teratozoospermia (n=227).