Quality of oocytes and embryos in patients with polycystic ovaries

Follicular metabolic changes and effects on oocyte quality in polycystic ovary syndrome patients

Polycystic ovary syndrome (PCOS) is a common complex and heterogeneous disorder, affecting up to 10% women at reproductive age. It causes three fourth of the ovulatory infertility and PCOS patients often give poor IVF quality. Although some metabolic profiles have been investigated in PCOS patient sera and urine, the follicular fluid, providing fruitful biochemical information about oocyte environment during development has been ignored. In this work, based on NMR metabolomics approach, metabolic profile of follicular fluid of PCOS patients has been explored and compared with healthy controls. Significant increases of glycoprotein, acetate, cholesterol, significant decreases of lactic acid, glutamine, pyruvate, and alanine, have been discovered in PCOS follicular fluids. Furthermore, the Pearson correlations analysis indicated significant relationship existed between ART results and NMR detected follicular metabolites. All these results indicated that PCOS may induce dyslipidemia, low-grade inflammation, and disorder of glycolysis, pyruvate and amino acid metabolism in follicular fluids.

Oocyte quality reflected by follicular fluid analysis in poly cystic ovary syndrome (PCOS): a hypothesis based on intermediates of energy metabolism

There is no clear acceptance of specific follicular fluid biomarker and its correlation with oocyte quality or related embryo variable till now. Most of the studies analyze correlation between certain biomolecules and the oocyte quality using single variable, instead of multivariate analysis algorithms. Our hypothesis is not based on single biomarker discovery, but attempts to explain oocyte quality in terms of energy metabolic pathways by considering its various intermediates. Reduced availability of glucose in the oocytes and follicular cells caused by defective transportation of glucose is expected in polycystic ovary syndrome (PCOS). This initiates alternative pathways to utilize fatty acid, amino acids etc. for energy as a compensatory mechanism to deal with the energy requirement. These compensations can be reflected by altered levels of various biomolecules in follicular fluid (e.g. ketone bodies, lipids, amino acids, lactate, pyruvate etc.). The amount of compensation, in order to meet the energy requirement can be directly correlated to quality of oocytes and better outcome after in vitro fertilization (IVF) in PCOS cases. This can be predicted with fair accuracy by doing a multivariate analysis of altered levels of various biomolecules in follicular fluid. Various supervised and unsupervised classification techniques based on spectroscopic data, obtained from follicular fluid samples may certainly prove to be an important tool to predict oocytes quality and IVF outcome with better accuracy in women with PCOS.

Extra- and intra-ovarian factors in polycystic ovary syndrome: impact on oocyte maturation and embryo developmental competence

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common metabolic dysfunction and heterogeneous endocrine disorder in women of reproductive age. Although patients with PCOS are typically characterized by increased numbers of oocytes retrieved during IVF, they are often of poor quality, leading to lower fertilization, cleavage and implantation rates, and a higher miscarriage rate.

METHODS

For this review, we searched the database MEDLINE (1950 to January 2010) and Google for all full texts and/or abstract articles published in English with content related to oocyte maturation and embryo developmental competence.

RESULTS

The search showed that alteration of many factors may directly or indirectly impair the competence of maturating oocytes through endocrine and local paracrine/autocrine actions, resulting in a lower pregnancy rate in patients with PCOS. The extra-ovarian factors identified included gonadotrophins, hyperandrogenemia and hyperinsulinemia, although intra-ovarian factors included members of the epidermal, fibroblast, insulin-like and neurotrophin families of growth factors, as well as the cytokines.

CONCLUSIONS

Any abnormality in the extra- and/or intra-ovarian factors may negatively affect the granulosa cell-oocyte interaction, oocyte maturation and potential embryonic developmental competence, contributing to unsuccessful outcomes for patients with PCOS who are undergoing assisted reproduction.