Impact of exosome-mediated feto-maternal interactions on pregnancy maintenance and development of obstetric complications.

Pregnancy is an immunological paradox, a phenomenon in which the foetus and the placenta, containing foreign antigens to the mother, develop without inducing rejection by the maternal immune system. Cell-to-cell communication between the foetus and the mother is mediated by secreted factors such as cytokines, hormones and extracellular vesicles (EVs) for a successful pregnancy and to avoid rejection. Exosomes, the smallest of EVs, are released extracellularly, where they are taken up by proximal or distant recipient cells. Here, we discuss the role of EVs, especially exosomes in feto-maternal communication during pregnancy. This review will provide an overview of the functional roles exosomes may play during embryo implantation, modulating immune responses during pregnancy and the onset of labour. Moreover, we will discuss exosomal function in obstetric pathology, and the development of pregnancy-associated complications such as preeclampsia and preterm birth as well as the biomarker potential of exosomes for detecting such conditions.