PRODUCTION OF REACTIVE OXYGEN SPECIES BY AND HYDROGEN-PEROXIDE SCAVENGING ACTIVITY OF SPERMATOZOA IN AN IVF PROGRAM

Purpose: Reactive oxygen species (ROS) including H2O2 produced by sper matozoa have been suggested, on one hand to be associated with idiopat hic male infertility and, on the other hand, to stimulate certain sper m function leading to fertilization. The influence of ROS on fertiliza tion was investigated in 75 IVF patients by correlating fertilization rates with the production of ROS and the H2O2-scavenging activity of s wim-up spermatozoa prepared in parallel with the IVF samples. Results: Low rates of ROS production by the swim-up sperm was detected by the luminol-dependent chemiluminescence assay. They were not correlated wi th fertilization rates. The hydrogen peroxide scavenging capacity of t hese spermatozoa, measured as the removal of exogenous H2O2 assayed sp ectrophotometrically, decreased stepwise in groups of patients achievi ng higher fertilization rates, suggesting a positive effect of this RO S on fertilization An alternative explanation of this correlation is p lausible in view of the association of both high scavenging activities and poor fertilization rates with poor sperm morphology. Conclusions: ROS produced by spermatozoa selected by swim-up plays no negative, if not a positive, role in fertilization.