Is NMR metabolic profiling of spent embryo culture media useful to assist in vitro human embryo selection?

The prediction of embryo viability by usual morphological analysis is currently unsatisfactory. New non-invasive techniques such as high-resolution nuclear magnetic resonance (H-1-NMR) spectroscopy that allows assessment of metabolic profiling in spent culture media might help embryologists to predict embryo development. Individual microdrops of culture media were analysed after 24 h of embryo culture (from day 3 to day 4) by spectroscopy using a 1 mm microliter probe allowing analysis without sample dilution. Embryos were divided into two groups on day 5: non-arrested embryos (n = 19) and arrested embryos unable to reach the blastocyst stage (n = 20). Multivariate analysis techniques such as Principal Component Analysis (PCA) and Orthogonal Partial Least Square Discriminant Analysis (OPLS-DA) were performed to compare extracellular metabolite balance. H-1-NMR used in combination with a 1 mm probe suggested that in vitro cultured human embryos that have a high developmental potential modify their environment slightly compared to embryos that cease to develop. However, differences between the two groups did not reach statistical significance and multivariate statistical analysis did not allow clustering of the two groups. This study indicated that this technique would not be sufficiently powerful alone to provide information that might help to assess the developmental potential of individual embryos for in vitro fertilisation (IVF).