The role of integrins in the formation of the placental increment (placenta accreta spectrum)

One of the most serious pregnancy complications is currently considered as a violation of cytotrophoblast invasion, particularly, a pathologically increased depth of invasion, leading to the formation of the placental increment (placenta accreta), ingrowth (placenta increta), and germination (placenta percreta). Cytotrophoblast invasion is regulated through subtle intercellular interactions, an important role among which is played by integrins, transmembrane glycoproteins that contribute to the immersion of cytotrophoblast in the endometrium and myometrium. The balance disturbance in the expression of 11, 51, and 64 integrins after normal implantation form a pathological extravillous trophoblast (EVT) phenotype by the blastocyst. This review examines the importance of integrins, collagens, and fibronectin in the formation of placental ingrowth (placenta accreta spectrum).