LAUSR

BACKGROUND Oxidative stress in semen contributes up to 80% of all infertility diagnosis. Diagnostics to measure oxidative stress in semen was recently added to the 6th edition WHO methods manual. Although, diagnostic predictive values need to be interpreted with caution as there are still several research questions yet to be answered. OBJECTIVES To determine the natural fluctuations in semen redox indicators (MiOXSYS® and OxiSperm® II) within and between men and their association with markers of sperm oxidative stress. MATERIALS AND METHODS Total, 118 repeat semen samples from 31 generally healthy men aged 18-45 years, over 6-months. Standard semen analysis as per 5th WHO manual. Semen redox levels measured via MiOXSYS® and OxiSperm® II. Additional attributes of sperm quality; HBA® binding assay and sperm hyperactivation and oxidative stress; DNA fragmentation (Halo® Sperm) and lipid peroxidation (BODIPY™ 581/591 C11) were assessed. RESULTS Samples with high redox-potential (MiOXSYS® ≥1.47 sORP/106 sperm/mL) had lower sperm concentration, motility, morphology and higher DNA fragmentation (P<0.05). Upon further analysis, these associations were driven solely by the adjustment of sperm concentration (106 /mL) in normalised redox-potential. No significant associations between NBT-reactivity (OxiSperm® II) and measures of sperm function or oxidative stress were observed (P>0.05). Fluctuations in semen redox levels varied greater between men than within men over the study period. DISCUSSION Neither MiOXSYS® or OxiSperm® II assays were predictive of sperm function or sperm oxidative stress. This was due at least in part to limited understanding of their biochemistry and clinical application. As a result, these assays seem to provide no additional clinical utility beyond that of a standard semen analysis. Highlighting the imperative for the development of new robust point-of-care devices for accurately determining sperm oxidative stress. CONCLUSION These findings suggest that MiOXSYS® and OxiSperm® II systems for the measurement of sperm oxidative stress have limited diagnostic potential. This article is protected by copyright. All rights reserved.