Table 4: Methodology, findings, and main conclusions derived from metabolomics studies on placenta tissues.

Population studyMaterialMetabolomic analysisMain resultsSignificance/take-home messagesReferenceAuthor, year

9 SGA cases
versus 8 controls
Placenta villous explantsUPLC-MS 574 metabolites were significantly different between SGA and controls; 49% of metabolites of interest were the same for SGA explant cultured under hypoxic conditions and controls cultured under normoxic conditions Changes in phospholipids, essential amino acids (tryptophan, methionine, and phenylalanine) concentrationsMetabolomics might predict SGA[11]Horgan et al., 2010

11 uncomplicated term pregnanciesPlacenta villous explantsGC-MSCultured in 1%, 6%, and 20% oxygen. Differences in 2-deoxyribose, threitol/erythritol, hexadecanoic acid Metabolomics can be applied to placenta studies and could help in detecting hypoxia [10]Heazell et al., 2008

6 cases of preeclampsia versus 6 controlsVillous trophoblastUPLC-MS 47 metabolites in preeclampsia-derived media cultured under normoxic conditions showed similarities to that of uncomplicated pregnancies cultured under hypoxic conditions. Alterations in glutamate and glutamine, leukotrienes and prostaglandins, kynurenine metabolismMetabolomics might predict preeclampsia of placental origin developed due to hypoxia[4]Dunn et al., 2009

8 cases of labor/Cesarean section at 3100 m versus 8 controls with labor/Cesarean section delivery at sea level Placenta1H NMR,
At sea level: metabolic markers of oxidative stress, increased glycolysis, elevated cholesterol, and free amino acids. At 3100 m: metabolic profiles with adaptation to chronic hypoxia, decreased reliance on anaerobic glycolysis; presence of concentrations of stored energy potential (phosphocreatine), antioxidants (taurine, inositol), and low free amino acid concentrationsMetabolomics might help identify subjects under hypoxic stress (chronic hypoxic preconditioning state versus acute ischemic/hypoxic insult)[6]Tissot van Patot et al., 2010

SGA: small for gestational age; UPLC-MS: ultra performance liquid chromatography-mass spectrometry; GC-MS: gas chromatography-mass SPECTROMETRY; 1H NMR: proton nuclear magnetic resonance spectroscopy; 31P NMR: phosphorus nuclear magnetic resonance spectroscopy.