Cross-sectional study of the sperm quality in semen samples from spinal cord injured men after long-term...

The deterioration of semen quality occurs very early after spinal cord injury (SCI). Thus, routine cryopreservation of semen early after injury has been recommended. However, there is currently a lack of data concerning the effects of long-term cryopreservation on the quality of spermatozoa from SCI men. We have therefore investigated the quality of spermatozoa from SCI men before and after long-term cryopreservation. The semen cryobank of a SCI rehabilitation center was screened for samples with a storage duration of more than 3 years, to carry out a cross-sectional study regarding the sperm quality of semen samples from SCI men. Semen quality analysis was carried out according to the WHO-Guidelines. The quality of 28 semen samples from 16 SCI men was investigated prior to and a median 11 years (95% CI 7-13 years) after cryopreservation. Prior to cryopreservation, ejaculate volume (median = 1.7 mL, 95% CI 1-3 mL) and sperm concentration (median = 106 × 10(6) /mL, 95% CI 82-132 × 10(6) /mL) were within normal limits, but total sperm motility (median = 19%, 95% CI 13-22%) and viability (median = 27%, 95% CI 19-45%) were reduced. Cryopreservation resulted in a significant (p < 0.0001) decrease in total sperm motility (median = 2.5%, 95% CI 0-4%) and viability (median = 7%, 95% CI 6-13%). There were no significant (p = 0.75) differences between the semen parameters of samples collected early (up to 3 weeks) after SCI and those collected later. Complete SCI had a significantly (p < 0.0001) negative effect on the sperm viability of the fresh semen samples, and tetraplegia had a significantly (p < 0.035) negative effect on both pre-cryopreservation sperm viability and post-cryopreservation motility. The assisted ejaculation technique had no significant (p > 0.053) effect on semen quality. Long-term cryopreservation of semen from SCI men results in essentially immotile sperm with minimal viability. Thus, routine long-term cryobanking of semen harvested early after SCI cannot be recommended.