The incidence and etiology of sperm DNA fragmentation in the ejaculates of males with spinal cord injuries

Study design Retrospective descriptive study. Objectives To determine the incidence and probable etiology of sperm DNA fragmentation (SDF) in a sample of males with spinal cord injury (SCI). Setting Hospital in Toledo, Spain; University-based Genetics laboratory in Madrid, Spain. Methods Semen collected by vibro-stimulation from 27 males with various levels of spinal cord injury. Classical semen parameters, SDF, leukocytospermia and pro-oxidant capacity were assessed and compared with a cohort of normozoospermic fertile donors ( n = 10). Results Males with SCI presented with lower semen quality compared with normozoospermic donors with respect to progressive motility ( p = 0.0002), SDF ( p < 0.00005), pro-oxidant capacity ( p = 0.0191) and leukocytospermia ( p < 0.00005). Although there was no significant correlation between semen quality and time since the lesion occurred, the period of abstinence appeared to be positively correlated with SDF ( r = 0.486; p = 0.041). When the semen parameters of males with SCI were categorized based on those with cervical and thoracic lesions, sperm concentration was higher for those with cervical damage ( p = 0.0257). Males with complete lesions (AIS A) had ejaculates that were lower in progressive motility ( p = 0.0040) than those with incomplete injuries (AIS B–D). Conclusions Ejaculates of males with SCI have excessively elevated SDF when compared with normozoospermic donors, which is likely to be associated with coincident high levels of leucocytospermia and pro-oxidant capacity. We propose that these phenomena are caused by the accumulation and degeneration of spermatozoa in the cauda epididymidis.