Impact of Blood Alpha-tocopherol Levels on Oocyte and Embryo Quality in Women Undergoing IVF/ICSI Treatment: A Cross-sectional Study

Abstract

Background: Evaluation of oocyte quality is one of the most important goals of embryologists in assisted reproductive technologies, due to its importance in successful fertilization and embryonic development. Females undergoing in vitro fertilization are exposed to massive systemic oxidative stress due to the ovarian stimulation protocols used, which negatively affects oocyte maturation and embryonic development. Vitamin E is one of the most important exogenous antioxidants purported to defend against oxidative stress by modifying free radical electrons, and therefore it is necessary to investigate the effect of its blood levels on oocyte maturation and the embryo quality in women undergoing in vitro fertilization treatment. Methods: An observational, cross-sectional study was conducted on 60 females undergoing IVF treatment by pituitary down-regulation with GnRH agonist. Alpha-tocopherol levels in the serum and the follicular fluid were determined using an HPLC kit for vitamin E (RECIPE, Germany). The maturity of the oocyte nucleus as well as the development of the resulting embryos after sperm injection are evaluated by the in vitro fertilization specialist. Grade Ι embryos resulting from the injection of high-quality oocytes (MΠ oocytes) are what the doctor seeks to obtain to return these embryos to the uterus. We investigated the relationship between serum alpha-tocopherol levels with the percentage of MΠ oocytes and Grade Ι embryos using Statistical Package for Social Sciences version 23, and a chi-square test was adopted to study differences in the distribution rates of the types of oocytes and embryos at different levels of vitamin E in the blood. Results: According to the blood vitamin E levels, a significant difference (p= 0.001) was found between the percentages of both MΠ oocytes and grade Ι embryos. The highest percentages were for levels (10-<15), followed by levels (5-<10), while the lowest percentages were seen for levels (15-20) mg/l of vitamin E in the blood for both, which were 68 and 62, 17 and 20, 15 and 17%, respectively. Conclusion: The highest ratio of both mature oocytes (MΠ) and high-quality embryos (Grade I) can be achieved at blood levels of alpha-tocopherol (10-<15) mg/l in women undergoing IVF-ICSI.