Background During pregnancy, there is an increase in the amount of extracellular vesicles, especially placental exosomes, in maternal plasma. Aim To isolate and characterize extracellular vesicles from blood during the three trimesters of pregnancy and to evaluate their capacity to identify patients at risk of developing gestational diabetes. Material and Methods A case-control study was conducted in a cohort of 50 pregnant women with plasma samples taken in each trimester. Six women who developed gestational diabetes were paired with three healthy controls per case (a total of 19). Clinical characteristics were recorded at first prenatal appointment, and blood samples were obtained during the first, second and third trimesters. Extracellular vesicles were isolated from plasma by the commercial kit, ExoQuick™. Nanoparticle tracking analysis, was used to characterize the obtained extracellular vesicles. Results The total concentration of extracellular particles isolated from maternal plasma increased along with gestational age. The size of the extracellular vesicles obtained in the first trimester of pregnancy was very similar between groups (144 ± 37 nm for controls and 143 ± 34 nm for patients with gestational diabetes mellitus). Moreover, the concentration of extracellular vesicles collected in the first trimester, was significantly higher in patients who developed gestational diabetes mellitus later in pregnancy compared to normoglycemic pregnant women (7.94 x 10 8 and 5.15 x 10 8 , p = 0.03). Conclusions Our results provide an insight into the potential capacity of first trimester plasma extracellular vesicles as early biomarkers for the prediction of gestational diabetes mellitus.