Negative effects of increased sperm DNA damage in relation to seminal oxidative stress in men with idiopathic and male factor infertility

Objective: To examine the effects of increased sperm DNA damage in relation to seminal oxidative stress in men with idiopathic and male factor infertility. Design: Prospective study. Setting: Infertility clinic at a tertiary care academic institution. Patient(s): Ninety-two infertile men with normal female partners. Sixteen fertile donors served as the control group. Intervention(s): Standard semen analysis and assessment of levels of seminal oxidative stress. Assisted reproductive techniques in 33 of the 92 patients (IUI [n 19], IVF [n = 10], and intracytoplasmic sperm injection [n = 4]). Main Outcome Measure(s): Sperm DNA damage by sperm chromatin structure assay. Results were expressed as DNA fragmentation index. Result(s): Patients were classified as having either idiopathic (n = 23) or male factor infertility (n = 69). Patients with idiopathic and male factor infertility had significantly higher DNA fragmentation index and oxidative stress compared with the case of fertile donors. A clinical pregnancy was achieved in 9 (27%) of 33 patients with assisted reproductive techniques. Significantly higher DNA fragmentation index and oxidative stress were found in men who failed to initiate a pregnancy after assisted reproductive techniques (n = 24), compared with the cases of those who succeeded and of the fertile donors. DNA fragmentation index was correlated positively with oxidative stress (r = 0.27), and negatively with fertilization (r = -0.70) and embryo quality (r = -0.70). Conclusion(s): Sperm DNA damage is significantly increased in men with idiopathic and male factor infertility and in men who failed to initiate a pregnancy after assisted reproductive techniques. Such an increase may be related to high levels of seminal oxidative stress.