Impact of Environmental Conditions During IVF Laboratory Handling on Sperm Quality

Spermatozoa are highly susceptible to environmental stress because of their limited antioxidant capacity and DNA repair mechanisms. During assisted reproductive technology (ART), semen samples are exposed to various laboratory conditions; however, current guidelines provide limited recommendations regarding optimal environmental parameters for sperm handling. The aim of this study was to evaluate the effects of environmental factors encountered in the ART laboratory on classical sperm parameters (total motility, progressive motility, and vitality) and functional markers, including oxido-reduction potential (ORP) and DNA fragmentation (DF). Normozoospermic native semen samples (n = 8) were exposed for 1 h to different temperatures (4, 24, 37, and -80 °C), oxygen concentrations (21 and 5%), visible or UV light, and centrifugation (400× g). UV irradiation and exposure to -80 °C exerted the most detrimental effects on classical sperm parameters. While -80 °C did not significantly affect ORP or DF, UV irradiation caused the most pronounced increases in both parameters. 5% O₂ and 4 °C preserved several sperm quality parameters more effectively than conventional laboratory conditions (21%, 24, 37 °C). These findings demonstrate that even short-term exposure to various laboratory conditions can substantially affect sperm quality. Modification of environmental conditions during sperm handling may therefore contribute to preserving sperm function during ART.