Metabolomic Signatures in Blastocyst Spent Culture Medium as Non-Invasive Predictors of Live Birth: A Pilot Study

Abstract

Research question: Can metabolomic profiling of blastocyst spent culture medium (SCM) serve as a non-invasive tool to predict live birth? Design: This pilot study investigated the association between metabolite profiles in SCM and clinical outcomes following single blastocyst transfer. Seventy SCM samples were analysed using untargeted liquid chromatography-mass spectrometry. Metabolites were identified via Human Metabolome Database and Compound Discoverer 3.3. Statistical analyses were performed using SPSS. Results: In total, 173 metabolites were detected in SCM samples. Six metabolites exhibited significant differences between the pregnancy and non-pregnancy groups, while 10 metabolites varied between the live birth and non-live birth groups. Notably, eicosapentaenoic acid, a polyunsaturated fatty acid, decreased in pregnancy cases. In contrast, 1-(4-methoxyphenyl)-3-pentanone and (2S)-2-(6-methoxynaphthalen-2-yl) propanoic acid were consistently elevated in both the pregnancy and live birth groups. Additional differential metabolites included L-glutamine, pyroglutamylglycine, alanylproline and 15,16-dihydroxyoctadecanoic acid, potentially reflecting implantation-related metabolic activity. Logistic regression and receiver operating characteristic curve analyses demonstrated acceptable predictive performance, with area under the curve values of 0.788 for pregnancy and 0.834 for live birth. Conclusions: Metabolomic profiling of SCM may offer a promising non-invasive adjunct to embryo selection strategies. While these findings suggest biological relevance of several metabolites, particularly lipids and amino acid derivatives, larger studies are needed to validate predictive value and clinical applicability.