The difference between the anterior and posterior walls of the placenta is mainly due to their different positions and different safety, etc. However, their differences often have little effect on pregnancy. 1. Different positions: the anterior wall of the placenta means that the placenta is attached to the front of the uterus, i.e. the abdominal side of the pregnant woman. The posterior wall of the placenta means that the placenta is attached to the back of the uterus, i.e. the dorsal side. 2. Safety is different: the front wall of the placenta is close to the belly, so if there is an accident such as impact, it is more likely to lead to the placenta after the impact, the formation of hemorrhage, the back wall of the placenta, the amniotic fluid can play a role in some protection. Whether it is the front wall of the placenta or the back wall of the placenta, is a normal pregnancy, it is recommended that pregnant women during pregnancy, regular obstetric examination in the hospital, under the guidance of obstetricians to do a good job of all kinds of care, the emergence of abnormalities in a timely manner.