Introduction. In modern reproductive medicine, increasingly attention is paid to pathospermia caused by the formation of oxidative stress, one of the causes of which is varicocele, leading to the formation of hyperthermia and testicular ischemia. The excess of reactive oxygen species, free radicals in the ejaculate during oxidative stress can provoke damage to spermatozoa at the subcellular level, leading not only to DNA fragmentation, but also damage to the acrosome, mitochondria, and increased apoptosis.

The purpose of the study: to assess the ultrastructure of spermatozoa in adolescents, to identify changes in spermatozoa characteristic of varicocele.

Material and methods. Electron microscopic examination of spermatozoa was performed on adolescents aged 17 years; 100 adolescents were diagnosed with left-sided varicocele; 30 teenagers without varicocele made up the comparison group.

Results and discussion. In adolescence, the typical ultrastructure of spermatozoa is most often detected. In adolescents with varicocele, damage to chromatin, acrosome, mitochonria was more often detected, but no statistically significant differences were found compared to adolescents without varicocele.

Conclusions. There were no specific changes in the structure of spermatozoa characteristic of varicocele.