Adipose tissue derived exosomes (exo-AT) have been reported to involve in a wide range of metabolic complications, including insulin action and glucose homeostasis. There are no studies, however, that have defined the potential role of exo-AT in pathogenesis of gestational diabetes mellitus (GDM). In the present study, we studied the protein content of exo-AT in normal glucose tolerant (NGT) and GDM pregnancies and their effect on placental glucose metabolism. Human omental adipose tissue were obtained from NGT (n=48) and GDM (n=60) pregnancies at delivery (>37 weeks gestation). Exosomes were isolated from tissue-conditioned media by differential centrifugation and characterised using nanoparticle tracking analysis (NanoSight) and their protein content was identified using SWATH mass spectrometry. The effect of exosomes on placental cells was evaluated using a Human Glucose Metabolism array kit. Ingenuity Pathway Analysis (IPA) of the exosomal proteins revealed differential expression of the proteins targeting sirtuin signalling pathway (SIRT), oxidative phosphorylation (OXPHOS) and mechanistic target of rapamycin (mTOR) signalling pathways in GDM compared to NGT. Exo-GDM on placental cells increased the expression of genes associated with glycolysis and gluconeogenesis compared with exo-NGT. The data obtained in this study suggest that AT exosomal signaling may play an important role in regulating placental glucose metabolism and contribute for the adverse consequences commonly observed in GDM pregnancies, such as fetal macrosomia.