PHYS30001 Lecture 34: 34 Preeclampsia placental and vascular origins A
Document Summary
Development of the maternal blood supply to the placenta is suggested to be complete by the end of the first trimester of pregnancy (approximately 12-13 weeks) Substitutes for fetal organs: lungs kidneys gastrointestinal tract. Provides fetus with oxygen and nutrients, and removes waste products. Fetal compartment: fetal arteries/veins in the chorionic plate. Maternal side: placenta supplied by endometrial/spiral arteries, blood drained by endometrial veins. Fetal-maternal interface is critical component of placental vasculature: contains umbilical arteries/veins in chorionic villi, bathed in maternal blood space. In normal placental development, cytotrophoblast cells invade the maternal spiral arteries (via remodelling), replacing the ec/smc. During this process, the cytotrophoblast cells differentiate from an epithelial phenotype to an endothelial phenotype. Enlarges the spiral arteries to increase blood supply to maternal-fetal interface. Loss of endothelial cells (but replaced by differentiated trophoblast cells) Arteries become wider to form high-flow, low resistance channels. Inadequate remodelling of the uterine spiral arteries leads to abnormal placental development and reduced placental perfusion.
