The reactive oxygen species—total antioxidant capacity score is a new measure of oxidative stress to predict male infertility

There is growing evidence that oxidative stress significantly impairs sperm function, and plays a major role in the aetiology The imbalance between reactive oxygen species (ROS) of defective sperm function. This may lead to the onset of production and total antioxidant capacity (TAC) in seminal male infertility via mechanisms involving the induction of fluid indicates oxidative stress and is correlated with male peroxidative damage to the plasma membrane (Jones et al., infertility. A composite ROS‐TAC score may be more 1979; Aitken and Clarkson, 1987; Iwasaki and Gagnon, 1992; strongly correlated with infertility than ROS or TAC alone. Aitken and Fischel, 1994; Sharma and Agarwal, 1996; Griveau We measured ROS, TAC, and ROS‐TAC scores in semen and Le Lannou, 1997). Both spermatozoa and seminal plasma from 127 patients and 24 healthy controls. Of the patients, possess antioxidant systems capable of counteracting the harm56 had varicocele, eight had varicocele with prostatitis, 35 ful affects of ROS. Studies have demonstrated that infertile had vasectomy reversals, and 28 had idiopathic infertility. men are more likely than fertile ones to have depressed total ROS levels were higher among infertile men, especially antioxidant capacity (TAC) and lower levels of individual those with varicocele with prostatitis (mean K SE, 3.25 K antioxidants (Smith et al., 1996; Lewis et al., 1995, 1997). 0.89) and vasectomy reversals (2.65 K 1.01). All infertile The production of abnormal levels of ROS is thought to be groups had significantly lower ROS‐TAC scores than con- involved in many aspects of male infertility, where spermatozoa trol. ROS‐TAC score identified 80% of patients and was are rendered dysfunctional by lipid peroxidation and altered significantly better than ROS at identifying varicocele and membrane function, together with impaired metabolism, moridiopathic infertility. The 13 patients whose partners later phology, motility, and fertility (Cummins et al., 1994). Men achieved pregnancies had a mean ROS‐TAC score of whose spermatozoa produce excessive ROS are less likely 47.7 K 13.2, similar to controls but significantly higher to impregnate their wives through natural intercourse. The than the 39 patients who remained infertile (35.8 K 15.0; incidence of spontaneous pregnancy is negatively correlated P < 0.01). ROS‐TAC score is a novel measure of oxidative with the generation of ROS in approximately 50% of oligozoostress and is superior to ROS or TAC alone in discriminat- spermic patients who exhibit increased ROS production (Aitken ing between fertile and infertile men. Infertile men with et al., 1991). male factor or idiopathic diagnoses had significantly lower Various clinical diagnoses are unable to determine the ROS‐TAC scores than controls, and men with male factor underlying cause of sperm dysfunction and pathophysiology diagnoses that eventually were able to initiate a successful of infertility. Since oxidative stress has been demonstrated to pregnancy had significantly higher ROS‐TAC scores than play a key role in male infertility, it is imperative to identify those who failed. measures that would help predict, with accuracy, if oxidative