37 Bioanalysis (2017) 9(1), 37–51 ISSN 1757-6180 part of Research Article 10.4155/bio-2016-0223 © 2017 Future Science Ltd 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. First draft submitted: 9 August 2016; Accepted for publication: 11 October 2016; Published online: 6 December 2016 Keywords: coelomic fluid • coelomic fluid cells • metabolomics Extra-embryonic coelom (EEC) is probably one of the least explored human body fluid cavities in the human body. EEC is the larg- est space inside the human gestational sac up to 9 weeks’ gestation [1] . After 10 weeks, the EEC starts shrinking with simultaneous expansion of the amniotic cavity. EEC pro- vides an essential nutritional pathway for the early fetus before the placental circulation is fully established. Analysis of the EEC con- tent (coelomic fluid [CF] and cells [CFC]) has been proposed for prenatal diagnosis. CF and CFC are collected by coelocentesis typically performed between 6 and 11 weeks of gestation by highly experienced special- ists. Coelocentesis is (in theory) an attrac- tive alternative for early amniocentesis and chorionic villous sampling because the risk of directly injuring the growing embryo or damaging its placenta is low [2] . Several authors have proposed the use of coelomic cells in prenatal diagnostics. For application of CFC in prenatal diag- nosis, different techniques have been used, including fluorescence in situ hybridization and polymerase chain reaction to identify fetal gender [3–5] , DNA amplification [6] to identify single gene disorders such as sickle cell anemia or β-thalassemia – [7] and stan- dard cytogenetic cultures [3] . Prenatal diag- nosis in the first trimester could provide early detection of genetic disorders, however, in two studies by Giambona et al. limitations due to contamination of samples with mater- nal cells are discussed. The cellular content of CF was investigated for any potential mor- phological discrimination between maternal and embryo–fetal cells. It was found that the CFC contained ten different cell types including six of maternal origin and four types of embryo–fetal cells [8] . Another study is mainly focused on isolation of fetal cells from celomic fluid [9] . Additionally it is important to mention that although coelocentesis has been pro- posed as an early prenatal diagnostic proce- dure there is very limited knowledge on the metabolic content of both CF and CFCs [10] . Metabolic profile of human coelomic fluid C Virgiliou 1 , L Valianou 1 , M Witting 2,3 , F Moritz 2 , C Fotakis 4 , P Zoumpoulakis 4 , A C Chatziioannou 1 , L Lazaros 5 , G Makrydimas 5 , K Chatzimeletiou 6 , N Raikos 7 & GA Theodoridis *,1 1 Department of Chemistry, Aristotle  University, Thessaloniki, Greece 2 Research Unit Analytical  BioGeoChemistry Helmholtz Zentrum  Munchen, German, Research Center for  Health and Environment Neuherberg,  Germany 3 Chair of Analytical Foodchemistry,  Wissenschaftszentrum Weihenstephan  für Ernährung, Landnutzunng und  Umwelt, Technische Universität München 4 Institute of Biology, Medicinal Chemistry  & Biotechnology, National Hellenic  Research Foundation, Athens, Greece 5 Department of Obstetrics & Gynecology,  Ioannina University Hospital, Ioannina,  Greece 6 Unit for Human Reproduction, 1st  Department of Obstetrics & Gynecology,  Medical School, Aristotle University of  Thessaloniki, Thessaloniki, Greece 7 Laboratory of Forensic Medicine &  Toxicology, Medical School, Aristotle  University of Thessaloniki, Thessaloniki,  Greece *Author for correspondence:  gtheodor@chem.auth.gr Special Focus Issue: Methods & Techniques for Metabolic Phenotyping For reprint orders, please contact: reprints@futuremedicine.com