Metabolomic Profiling Identifies Stage of Oocyte Maturation in IVF

Differences in oocyte metabolic activity were consistently demonstrated among the metabolomic profiles of oocyte maturity (OM) biomarkers in culture media from oocytes at specific maturational stages.

The study's objectives were to determine whether novel metabolomic profiles, or "fingerprints,” could be established using near infrared spectroscopic analysis (NIR) of specific biomarkers from culture medium obtained from oocytes at different maturational stages (metaphase I and II, prophase I). A secondary objective was to determine how metabolomic profiles obtained from oocyte medium correlated with the egg's oxidative metabolism, or the state of the cell's respiratory processes. These processes are closely tied to oocyte quality and may prove useful in predicting post-fertilization developmental capacity and embryo quality.

Based on rapid, non-invasive NIR analysis of specific novel biomarkers in oocyte culture media, the investigators identified unique metabolomic profiles for eggs at each of the three developmental stages. These data were correlated with microscopic morphologic assessment of nuclear maturity of the corresponding oocytes using multivariate analyses with a P level of 5%. Profiles of metaphase I and II (M I and M II) oocytes differed significantly from each other and from profiles of prophase I (GV) oocytes (p < 0.001 at the 95% confidence interval).

James Posillico, Ph.D., president and CEO of Molecular Biometrics, commented on the study, "The ability to confirm stages of oocyte maturation using rapid, non-invasive metabolomic profiling may offer an altogether new method to help IVF [in vitro fertilization] practitioners ensure development of a viable embryo with high reproductive potential. With further developmental work, we believe these findings may serve as the cornerstone of a non-invasive test of oocyte maturation that is based on objective biological metrics of cellular metabolism. Such a test could be used in conjunction with morphological criteria for identifying high quality pre-fertilization oocytes.”

The study was conducted by scientists from Reproductive Biology Associates (RBA; Atlanta, GA, USA) and the Embryology Laboratory, Stanford University (Stanford, CA, USA) in collaboration with Molecular Biometrics and the department of chemistry, McGill University (Montreal, Canada). The findings were reported by Molecular Biometrics, a privately held metabolomics company, at the American Society of Reproductive Medicine's 63rd Annual Meeting (ASRM), which was held in Washington, DC (USA), in October 2007.

Principal investigator, Zsolt Peter Nagy, M.D., Ph.D., scientific and laboratory director at Reproductive Biology Associates, said, "Non-invasive assessment of gametes and embryos opens new frontiers in reproductive medicine. Establishing correlations between metabolomic fingerprints of oocyte and embryo development and embryo viability will be a critical contribution to improve efficiency of assisted reproduction treatment procedures. This test may be the first, objective, operator-independent procedure that all IVF professionals--and patients--were awaiting for decades. We expect that this platform will contribute to progress in many different aspects of embryology and will result in improved patient care in IVF.”


Related Links:
Reproductive Biology Associates
Stanford University
McGill University