RESUMO
The relationship between oxidative stress and unexplained infertility (UEI) has not been studied in detail. This is the first study to evaluate dysfunctional high-density lipoprotein (HDL) by the myeloperoxidase (MPO) and paraoxonase (PON) ratio to investigate the role of oxidative stress in UEI. MATERIALS AND METHODS: Patients with UEI (study group, n = 40) and male factor infertility (control group, n = 36) were included in this prospective study. Demographics and laboratory assessments were analyzed. RESULTS: Total dosages of gonadotropin were higher in UEI when compared to the control group (p = 0.033). Number of Grade 1 embryos and the quality of blastocysts were lower in UEI than in the control group (p = 0.024, p = 0.020, respectively), whereas serum MPO/PON ratio was higher in UEI (p = 0.042). Stepwise linear regression analysis revealed that serum MPO/PON ratio levels could significantly predict the duration of infertility (p = 0.012). CONCLUSIONS: Serum MPO/PON ratio increased in patients with UEI, whereas the number of Grade 1 embryos and the quality of blastocysts decreased. Similar clinical pregnacy rates were found in both groups but the ET on day five is associated with higher clinical pregnancy rate in the male factor infertility.
