trophoblast cell extravillous trophoblast 2020-03-02T08:45:06Z extravillous cytotrophloblast EVT A trophoblast cell that is not part of a placental villous. Extravillous trophoblasts (EVTs), a specialized subset of trophoblast cells, play crucial roles in establishing and sustaining pregnancy. Firstly, they anchor the fetus to the maternal tissue, providing structural stability. Secondly, they are instrumental in modifying the maternal spiral arteries to ensure an adequate supply of maternal blood to the placenta and the developing fetus. EVTs invade maternal decidua and myometrium and replace the endothelial lining of the spiral arteries, transforming these high-resistance, narrow vessels into low-resistance, wide vessels, favouring higher blood flow. Thirdly, these cells also play an immunological role, creating an environment conducive to the acceptance of the semi-allogeneic fetus, by expressing non-classical MHC molecules, thereby averting any potential maternal immune response towards fetal tissues. While EVTs are commonly associated with healthy pregnancies, abnormalities in their function or development have been connected to problematic pregnancies. Conditions like pre-eclampsia and fetal growth restriction (FGR) may arise if EVT cells do not effectively invade the maternal decidua or adequately remodel. (This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies only to some subtypes and species, and so should not be considered definitional.) https://cellxgene.cziscience.com/cellguide/CL_0008036