Sperm quality assessed by flow cytometry and accessory sex gland function in spinal cord injured men after repeated vibration-induced ejaculation

Abstract

Semen was obtained by vibration-induced ejaculation from 5 spinal injured men once a week for 5 consecutive weeks under standardised conditions. The site of the spinal lesions varied from C5 to Th10. Although in all subjects except one, the total sperm count in the first ejaculate was within normal limits, conventional criteria indicated a high degree of asthenoteratozoospermia in all cases. In subsequent ejaculates there was no major general improvement in motility, vitality or morphology. However, 2 individuals exhibited a marked increase in the proportion of motile sperm in the ejaculate over the next 3 weeks. Flow cytometry of the same sperm samples indicated a high degree of abnormal chromatin condensation and reduced binding of a fluorescent acrosomal marker in the first ejaculates. No improvement in these parameters could be detected with time. Assessment of accessory sex gland function using specific secretory markers indicated that compared to the normal population, the vesicular contribution was markedly reduced in 3 subjects and prostatic contribution in the 2 remaining subjects in the first and subsequent ejaculations. Ejaculate volumes were consistently low in all subjects during the observation period. In contrast, total epididymal secretion was comparable to normal ejaculates. Prostatic contributions to the ejaculate increased significantly over the first 4 weeks. In conclusion, regular vibration-induced ejaculation at weekly intervals could not improve sperm quality in paraplegic men to an acceptable degree for assisted fertilisation to be recommended. Although certain aspects of sperm quality, as judged by conventional criteria, were improved in some cases, flow cytometry revealed persistent chromatin and acrosomal abnormalities.