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. Prospective study. SETTINGS 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.