Predictors of necrospermia in men with spinal cord injury

Purpose: We identify predictors of the lowest yield of dead sperm in ejaculates of men with spinal cord injury. Materials and Methods: The percentages of dead immotile sperm and dead total sperm were compared in 141 spinal cord injured and 52 normal men, Predictors of necrospermia investigated in spinal cord injured men included specimen collection by vibratory stimulation versus electroejaculation, residence of sperm in antegrade versus retrograde specimens and level of injury. Results: Spinal cord injured subjects had a significantly higher percentage of dead sperm in the immotile fraction and total specimen than control subjects. The percentage of dead sperm was lower in antegrade versus retrograde specimens and in specimens produced by vibratory stimulation versus electroejaculation. There was no difference in the percentage of dead sperm by level of injury. Conclusions: Of the parameters evaluated only method and type of specimen collection were predictive of the degree of necrospermia in men with spinal cord injury. Level of injury was not predictive. The ratio of dead-to-live immotile sperm in spinal cord injured men was double that in normal men, indicating a pathological mechanism for sperm cell death.