From "Every Day" Hormonal to Oxidative Stress Biomarkers in Blood and Follicular Fluid, to Embryo Quality and Pregnancy Success?

Background. Oxidative stress appears to be involved in oocyte growth and maturation that when impaired results in poor embryo quality and lower potential to implant. The biochemical microenvironment of the oocyte (follicular fluid (FF)) consists of hormones and other various substances regulating the balance between oxidants and antioxidants. Aim. The aim of this study was to examine the possible impact of selected biomarkers ("every day," hormonal biomarkers, enzymatic and nonenzymatic antioxidants, and also oxidative stress markers) in serum and FF, on embryo quality and pregnancy success in infertile women undergoing infertility treatment. Methods. All 53 patients, mean age 34.7 +/- 4.1 years, with serum AMH level >= 0.7 ng/mL, were diagnosed with idiopathic infertility. They were stimulated in short antagonist protocol, followed by in vitro fertilization (IVF-ICSI intracytoplasmatic sperm injection) and a single embryo transfer. Follicular fluid was aspirated from the first mature follicle. In statistical analyses the R software was used, then all data was assessed with the Shapiro-Wilk test, logistic regression, and later the receiver operating characteristic (ROC) curve was applied using "pROC" R package. Results. We did not observe any correlation between AMH and embryo quality and pregnancy rate. Statistically significant results were only found for biomarkers examined in follicular fluid. Greater levels of GPX in FF were associated with the increased chance of producing a high quality embryo (the optimal cut-off concentration was established at over 450 lU/L.) Regarding pregnancy success, increasing levels of GR (cut-off at 21 IU/L), CuZnSOD (cut-off at 9NU/mL), and GST (cut-off at 2.5 IU/L) resulted in lower chances of a successful pregnancy. Conclusion. Our results indicate that FF markers may have some advantages in predicting embryo quality and pregnancy over AMH. The GPX system seems to be mostly related to embryo quality and pregnancy.