The placenta is an appendage of the fetus and plays a very important role in the growth of the fetus. If abnormalities occur, it may cause some harm to the mother or the fetus. In a normal pregnancy, the placenta is attached to the anterior, posterior or lateral wall of the uterus, and if the placenta is in the posterior wall of the uterus, it is a normal position. After 28 weeks of gestation, if the placenta is attached to the lower part of the uterus and the lower edge reaches or covers the inner cervical opening and is lower than the fetal previa, it is called placenta praevia. If the placenta is located in the lower segment of the uterus and the edge of the placenta is extremely close but does not reach the internal cervical os, it is called a low lying placenta. The relationship between the lower edge of the placenta and the endocervical opening can also change due to the loss of the cervical canal and dilatation of the uterine opening.