Understanding subfertility at a molecular level in the female through the application of nuclear magnetic resonance (NMR) spectroscopy

BACKGROUND: Understanding the aetiology of subfertility and female reproductive tract disorders at a molecular level may improve success rates in fertility treatment. Such understanding may be gained by the application of metabonomics technologies to tissues or biofluids. Metabonomics is concerned with the quantification of molecules in the metabolome and uses nuclear magnetic resonance (NMR) spectroscopy as one of the main technological platforms. This review concentrates on NMR studies of the female reproductive tract and discusses further possible applications. While full metabolic profiling is relatively recent, targeted NMR studies of biofluid and tissue has a longer history. METHODS: Searches were carried out on MEDLINE(®), PubMed, SciFinder(®) Scholar 2007 and ISI Web of Knowledge(SM) for papers about NMR spectroscopy or metabonomics of the female reproductive tract and subfertility. RESULTS: NMR spectroscopy has been employed for the compositional analysis of various elements of the female reproductive tract, including cervical mucus, follicular fluid (FF), ovarian tissue, fallopian tubes and uterine matter. NMR was used to document for the first time a change in FF lipoprotein concentration during follicular development. NMR analysis of granulosa cells from rats has revealed that follicle-stimulating hormone increases the activity of the pentose pathway, having crucial implications for ovarian stimulation regimens. In the uterine matter work, it has been shown by NMR that glycolysis is rapidly stimulated by estrogen, and in another study, citrate in uterine fluid was found as a potential biomarker for adenomyosis. NMR has also been used to show that chlamydiae are able to achieve higher energy reserves by stimulating glucose transport in host cells. CONCLUSIONS: A range of NMR spectroscopic techniques have been applied to the analysis of the female reproductive tract, however great potential remains for further studies. Incorporation of metabonomics techniques into female fertility research may be valuable for understanding subfertility and predicting outcomes of assisted conception treatments.