To investigate the metabolomic signature of trisomy 21 preimplantation human embryos by a noninvasive approach using mass spectrometry- (MS-) and nuclear magnetic resonance spectroscopy- (NMR-) based metabolic profiling platforms. A total of 171 spent media samples were collected from day 3 embryos and comparatively analyzed by MS analysis (chromosomally normal embryos, n = 15; trisomy 21 embryos, n = 15) and a matched control media group (without embryo, n = 14) and by NMR spectroscopy (normal embryos, n = 39; trisomy 21 embryos, n = 35; monosomy 21 embryos, n = 24) and a matched control media group (without embryo, n = 29). IVF clinic/preimplantation genetic diagnosis (PGD) unit facilities. One hundred seventy-one spent media samples obtained from human IVF embryos from patients included in our PGD program. Metabolomic profiling of embryo spent media using liquid chromatography/gas chromatography coupled with MS and NMR. Comparative identification of the metabolites present in the spent media from normal versus trisomy/monosomy 21 day 3 embryos. Two metabolites, caproate and androsterone sulphate, and two unknown compounds were differentially expressed between normal and trisomy 21 day 3 embryos. Furthermore, the NMR results indicate that there could be a correlation between the differences found between trisomy 21/monosomy 21 and the normal embryos in a spectral region compatible with isoleucine. This study suggests that the use of differential metabolomic markers found in spent media from preimplantation embryos could be a feasible method for the detection of aneuploidies before ET. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.