Pregnancy is the biggest event in a woman’s life and it is so wonderful to go through it safely. But once placenta praevia occurs, then all that goodness will turn into a woman’s nightmare. Is placenta previa that scary? The answer is yes. Placenta praevia is one of the main causes of bleeding in late pregnancy and is a serious complication of pregnancy. What is placenta praevia? To put it simply, when the placenta is attached to the edge of the cervix, or like a little cap over the top of the cervix, it is called placenta praevia. A normal placenta attaches to the front, back and side walls of the uterus. The main symptom of placenta praevia is painless vaginal bleeding. Symptoms mostly occur in late pregnancy, but usually there is a history of small amount of bleeding in early or middle pregnancy, and there is no sensation before or during the bleeding, and rarely there is mild abdominal discomfort. The first bleeding is usually not much, and most of them can be stopped naturally in a short period of time, and rarely there is fatal hemorrhage, and then it often recurs later, and the amount of bleeding also increases gradually. In severe cases, the normal pregnancy will be affected, and termination of pregnancy is necessary as a last resort. Placenta praevia has such harm, we not only have to ask, what are the causes of placenta praevia? The reasons are as follows: 1, multiple pregnancies, multiple abortions, multiple scraping operations and cesarean section surgery, etc., can cause damage to the endometrium, when the fertilized egg implanted in the uterine metaphysis, due to the lack of blood supply, in order to take in enough nutrients and the placenta area to expand, and even stretch to the lower part of the uterus. The incidence of placenta previa in twin fetuses is twice as high as in single fetus. This is because the placenta of twin fetuses is larger than that of a single fetus and can easily reach the lower part of the uterus. 3.When the fertilized egg arrives at the uterine cavity, its trophoblast layer develops slowly and continues to transplant into the lower uterine segment before it reaches the stage of being able to implant, and grows and develops there to form placenta praevia. 4, placental abnormalities, such as parietal placenta, the main placenta in the body of the uterus, while the parietal placenta can reach the lower part of the uterus near the endocervical opening. 5, is a hypothetical cause, is during pregnancy pregnant women smoking and harmful substances, easy to affect the uteroplacental blood supply, the placenta in order to obtain more oxygen supply and expand the area, may cover the cervical internal os, the formation of placenta previa.