Aim: Till now there is very limited knowledge on the molecular content of coelomic fluid and cells. This study presents the first attempt to elucidate the metabolic profile of such samples. Methodology: Samples were collected via coelocentesis from 41 women during the first trimester of gestation. Metabolic content was assessed using four different analytical platforms. For targeted analysis a hydrophilic interaction chromatography ultra high performance LC-MS/MS method was applied. Holistic analysis performed by GC-MS, NMR spectroscopy and ion cyclotron ultra-high resolution MS (FT-ICR-MS) instrumentation. Results & Conclusions: Our observations suggest coelomic fluid and cells as promising biosamples, rich in metabolites with potential use in mammalian system biology studies.