Impact of oxidative stress on semen parameters in normozoospermic infertile men: a case–control study

Background Oxidative stress has been implicated in male infertility through decrease in sperm quality. However, men with normal semen parameters (normozoospermia) may be unable to fertilize their partners even when they have normal sperm function. Thus, they would be considered infertile. The purpose of this study was to investigate the role of oxidative stress in the pathogenesis of unexplained male infertility. Methods In this case–control study, infertile men with normozoospermia ( n = 46) and fertile control group ( n = 21) underwent seminal fluid analyses according to WHO 2010 criteria. Serum and seminal plasma levels of total antioxidant capacity (TAC), glutathione, malondialdehyde, uric acid and albumin were also measured using colorimetric methods. Results The level of total antioxidant capacity in both serum and seminal plasma was significantly lower in normozoospermic infertile men in comparison with fertile group ( p < 0.0001). However, no significant differences were observed in serum and seminal plasma levels of glutathione, uric acid, albumin and malondialdehyde between infertile and fertile groups. Conclusion Low TAC level induces oxidative stress and consequently causes sperm dysfunction and male infertility. Estimation of TAC can be a useful tool in the diagnosis of male infertility. Antioxidant supplementation should be considered in the treatment of oxidative stress-induced male infertility.