Telocytes of placental villi were studied by electronic microscopy during physiological pregnancy. Ultrastructural features of telocytes indicating their heterogeneity and presence of at least three types of villi depending on their localization and kind were observed. All placental telocytes were characterized by small amount of organelles including mitochondria. Presence of long thin processes, which generated a branching network by contacting with each other, served as a typical feature of telocytes including telocytes of the stroma and intermediate villi. Telocytes were absent in the terminal villi.
Keywords: fibroblast; myofibroblast; physiological pregnancy; telocyte; villous tree of the placenta.