A minority of men with spinal cord injury have normal semen quality--can we learn from them? A case-control study

Abstract

Objectives: To determine factors that may help predict normal semen quality in this unique population of male patients, we examined our large database of men with spinal cord injury (SCI). Most men with SCI have abnormal semen quality; however, a small minority retain normal semen parameters.

Methods: A retrospective analysis was performed on semen retrieval procedures administered between 1991 and 2009 in 500 men with SCI. From those men, we selected subjects who underwent at least 1 penile vibratory stimulation, electroejaculation, or masturbation procedure resulting in antegrade ejaculation (n = 400). Cases were defined as men who, according to World Health Organization criteria, had normal semen volume, sperm concentration, sperm motility. Control subjects (CR) were defined as all remaining subjects. Risk factors for normal semen parameters were evaluated by conditional logistic regression analysis.

Results: Of the 400 subjects evaluated, only 30 had normal semen parameters. These 30 CS subjects were matched to 120 CR subjects. Analysis of risk factors revealed that incomplete lesion of the spinal cord (ASIA B to D) was significantly associated with the presence of normal sperm parameters (odds ratio 2.6 [95% confidence interval 1.1-6.1], P = .028). CS subjects were also more likely to be able to collect their samples via masturbation (odds ratio 2.7 [95% confidence interval 1.1-7.1], P = .037). Other risk factors evaluated were not predictive of normal semen parameters.

Conclusions: This retrospective, case-control study, performed on a large group of subjects, showed that completeness of SCI is an important risk factor influencing semen quality.