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The environment of the oocyte during its in vivo maturation consists of follicular fluid (FF) and is surrounded by granulosa cells. The FF is derived from the sanguineous plasma and secretions, synthesised in the follicle wall, that contain a large variety of growth factors, cytokines, amino acids, and other metabolites. These metabolites are presumably involved in the physiology of the oocyte. The identification, quantification and study of FF metabolites can provide additional information about the oocyte state which can be helpful in distinguishing those oocytes that have a greater capacity to be fertilised and to develop properly. The aim of this work is to identify the metabolic profile of FF samples exhaustively using High Resolution Nuclear Magnetic Resonance (NMR). A total of 30 FF samples from oocyte donors (<35 years) were analysed. Different monodimensional (1D) and bidimensional (2D) (homo and heteronuclear) NMR experiments were acquired. A total of 131 chemical shifts were assigned and 42 metabolites, including as example glucose, lactate, acetate, acetoacetate, pyruvate and beta-hydroxybutyrate, were identified. High correlations were found between these important intermediaries of the energetic metabolic pathways of the follicle which can indicate the importance of these pathways in oocyte development. Some of these identified metabolites might be useful as biomarkers of the follicular maturation state, allowing oocytes with a higher fertilisation potential to be selected, thereby increasing pregnancy rates in women following in vitro fertilisation (IVF) treatments.

Objectives: To evaluate the influence of numerical chromosomal abnormalities on preimplantation embryo development., Methods: This study includes 6936 embryos from 1245 women undergoing preimplantation genetic diagnosis (PGD). Indications for aneuploidy screening were: recurrent miscarriages, implantation failure, severe male factor, advanced maternal age, and mixed causes. Embryo biopsy was performed on day 3, and embryos were co-cultured until day 5, when embryo transfer was performed., Results: In the aneuploidy screening regimen, normal euploid embryos showed significantly higher blastocyst rates (68.2%) compared to chromosomally abnormal (42.8%, p < 0.0001) and mosaic (53.7%, p < 0.0001) embryos. Among aneuploid embryos for autosomes, higher blastocyst rates were observed in trisomies than monosomies, although only statistically significant in patients over 36 years of age (50.8 vs 38.9%; p < 0.0001). In contrast, in embryos with sex chromosomes aneuploidy, similar blastocyst rates were observed between trisomies and monosomy X., Conclusion: Embryos with certain types of chromosomal abnormalities were negatively selected during preimplantation embryo development. Despite this selection, a remarkable percentage of chromosomally abnormal embryos can develop normally to blastocyst stage with high probability of implantation and pregnancy., (Copyright (c) 2007 John Wiley & Sons, Ltd.)