Generally speaking, the placenta grows upwards around 28 weeks of pregnancy. around 10 weeks the placenta just starts to form, the vast majority of which is far away from the endocervical os, and slowly moves upwards as the uterus grows. The placenta is an important organ for the exchange of materials between the fetus and the mother, and its main role is to provide nutrition for the development of the fetus and increase the immunity of the fetus. In early pregnancy checkups, ultrasound can be used to measure the NT to be able to observe the placenta’s condition. The placenta’s starting position is low, and as the uterus grows in the later stages, the placenta is also uplifted, and its position is gradually lifted upwards. If the placenta remains low, it may be placenta praevia, which may cause heavy bleeding during pregnancy or labor, which can be life-threatening, and needs to be clearly diagnosed under the guidance of a doctor. Pregnant mothers should undergo regular checkups, and if any of the above symptoms occur, they should seek prompt medical attention to clarify the cause of the disease and treat the symptoms, so as to avoid delaying the treatment.