The cotyledons that are visible on the maternal surface of the placenta show a good correspondence to the position of the villous trees derived from the chorionic plate in the intervillous space or blood chamber (Huppertz; Prieto Gomez et al., 2008; Carlson).
This decrease in p[O.sub.2] is the result of a reduced maternal blood supply flowing into the intervillous space, leading to the development of diabetic endarteritis and resulting in damage to the endothelial cells followed by their proliferation, which can lead to a narrowing of the maternal blood vessel lumens, reducing the uteroplacental circulation.
The prevalence of immature intermediate villi and villi with vessels near the center of the stromal region as well as the presence of increased cytotrophoblasts or those in proliferation and the nonexistence of syncytial bridges in the intervillous space have been considered determining factors of immaturity of the villi during the first trimester of a normal pregnancy.
Plasmodium falciparum-infected erythrocytes adhere both in the intervillous space
and on the villous surface of human placenta by binding to the low-sulfated chondroitin sulfate proteoglycan receptor.
The increased turbulence in the intervillous space
may damage the syncytium and increase perivillous fibrin deposition, so both the chronic injury of the perfusion of the placenta and/or nutritional deprivation could eventually lead to impaired development of the villi (5).
The intervillous spaces were of different sizes, but some of the spaces were wider than in normal placentae due to intervillous edema with increased content of fibrinoid material (Fig.
The villous blood vessels contain the fetal blood, while the intervillous spaces contain the maternal blood.
Additionally, the peripheral thick-walled vessels showed the same thick placental barrier leading to decreased oxygen and nutrient transfer from the mother to the fetus, due to the increased distance between the maternal blood in the intervillous spaces and the fetal blood in the blood vessels of the villi (Teasdale, 1981).
Because there is insufficient invasion of extravillous trophoblasts into the uterine vasculature, placental vascular resistance is not reduced; there thus is inadequate oxygenation of blood within the placental intervillous spaces that border villous trophoblasts.
If there is indeed a correlation between fetal DNA concentrations and trophoblast damage, hypoxia within the intervillous spaces might be more pronounced in cases of SPE than cases of mild PE.
Staining for [beta]hCG was prominent in vesicles separating from syncytiotrophoblast into the intervillous space
The thickness increases during contraction due to distension of intervillous spaces
by maternal blood.