Extracellular vesicles as critical mediators of maternal-fetal communication during pregnancy and their potential role in maternal metabolism

Extracellular vesicles (EVs) have been implicated in the pathophysiology of metabolic disorders by transferring biologically active molecules such as miRNAs and proteins to recipient cells, and influencing their metabolic pathways. Pregnancy is one of the greatest metabolic challenges faced by both the mother and the growing fetus, and this is fine-tuned by several factors, including hormones, soluble molecules, and molecules encapsulated in EVs released from the placenta. A wide range of EVs originating from the placenta are present in maternal circulation, and changes in their circulating levels and bioactivity (i.e., capacity to induce changes in the target cells) have been associated with several complications of pregnancies, including gestational diabetes mellitus (GDM), preeclampsia, preterm birth, and fetal growth restriction. Complications of pregnancies are associated with maternal metabolic dysfunction with short- and long-term consequences for both mother and child. However, the potential roles of circulating EVs originating from the placenta and other tissues (e.g. adipose tissue), on changes in maternal metabolism during normal and pregnancy complications have not been fully described. The aim of this brief review, thus, is to discuss the diversity of EVs, and their potential roles in the metabolic alterations during pregnancy, with a special focus on GDM.