Chorion is one of the membranes of the placenta. It is a part of the placental barrier (is its middle layer) and plays a big role in the metabolism of the fetus. In midwifery, the phrase "chorion presentation" is not entirely true, because it is only one of the placental membranes (medium), so the phrase "placental arrangement" is more often used. The preferred location of the chorion is the uterus bottom or the upper segment of the posterior wall. But sometimes the chorion is located on the front wall of the uterus or in the lower segment of the uterus. In this article, we will consider the features of the course of pregnancy when the chorion is localized along the anterior wall.
Chorion location options
The most frequent localization of the chorion is the posterior wall of the uterus with the transition to the lateral surfaces, with this arrangement of the chorion, the most favorable course of pregnancy. Localization of the villous chorion along the front wall is considered a variant of the norm. If the chorion is located high on the anterior wall, then there is no threat for the course of pregnancy (at least 3 cm from the inner throat of the cervix).
Chorion appears early in the formation of the embryo, it is responsible for feeding the future fetus before the 13th week of pregnancy. From the 13th week, this function is assumed by the placenta. Initially, the chorion has the appearance of small outgrowths surrounding the embryo, subsequently these outgrowths increase and turn into chorionic villi.
Presentation of the chorion
The presentation of the chorion on the back wall or anterior wall poses a threat to the course of pregnancy. Allocate marginal presentation (the edge of the placenta partially closes the inner cervical cervix) and full presentation (the placenta completely covers the inner cervical cervix). Such pregnant women need special supervision, since they are at risk of obstetric hemorrhages. If the presentation of the chorion occurs along the anterior wall, the risk of bleeding is somewhat higher, because the lower segment of the anterior wall of the uterus stretches better and faster and sometimes outruns the growth of the placenta than causes bleeding.
We examined the features of the course of pregnancy when the chorion is localized along the front wall. In the case when the chorion is located in the upper third of the uterus of pregnancy nothing is threatened. If the chorion is attached to the anterior wall of the uterus, in its lower third, the risk of premature placental abruption increases.