Fetal blood vessels subdivide from the umbilical cord and spread diagonally throughout the parenchyma towards the edge of the placental plate.In a circumvallate placenta, the membranes often become restrained due to marginal infarct, hemorrhage, or fibrin depositing. This results in the reduction in size of the chorionic plate of the placenta, further causing the membranes on the fetal side to fold backward on themselves. The parenchymal villous chorion continues to proliferate beyond the tethered membranes and appears to protrude outward. The fetal blood vessels are directed downward and then horizontally in order to provide blood flow to the most peripheral parts of the placental plate extending beyond the tethered membranes.Since a portion of the placenta tends to become exposed in a circumvallate placenta, due to the reduced size of the chorionic plate, vaginal bleeding is more likely to occur at this site of exposure. Likewise, inhibited fetal growth can also ensue due to the decreased exchange of nutrients and waste between mother and fetus, since the fetus is unable to sustain necessary nutritional demands for proper fetal development. Premature rupture of membranes often occurs as a result of infection in the uterus, which can be caused by the occurrence vaginal bleeding. Therefore, placental abnormalities such as circumvallate placenta can be extremely detrimental in causing the onset of associated conditions. Diagnosis
In some cases, a physician may be able to diagnose a circumvallate placenta via ultrasound during one of many routine ultrasound screenings.
Ecotourism also has an effect on species through the value placed on them. "Certain species have gone from being little known or valued by local people to being highly valued commodities. The commodification of plants may erase their social value and lead to overproduction within protected areas. Local people and their images can also be turned into commodities". Kamuaro points out the relatively obvious contradiction that any commercial venture into unspoiled, pristine land inevitably means a higher pressure on the environment. The people who live in the areas now becoming ecotourism spots have very different lifestyles than those who come to visit. Ecotourism has created many debates based on if the economic benefits are worth the possible environmental sacrifices. Who benefits? Most forms of ecotourism are owned by foreign investors and corporations that provide few benefits to the local people. An overwhelming majority of profits are put into the pockets of investors instead of reinvestment into the local economy or environmental protection leading to further environmental degradation. The limited numbers of local people who are employed in the economy enter at its lowest level and are unable to live in tourist areas because of meager wages and a two-market system.In some cases, the resentment by local people results in environmental degradation. As a highly publicized case, the Maasai nomads in Kenya killed wildlife in national parks but are now helping the national park to save the wildlife to show aversion to unfair compensation terms and displacement from traditional lands.