The lower edge of the placenta reaches 17mm at the endocervical opening at 13 weeks of pregnancy suggests that the placenta is in a low position, and it needs to be rechecked on time in accordance with the doctor’s instructions, and it is a state of abnormality. When the lower edge of the placenta reaches 17mm at the endocervical os at 13 weeks of pregnancy, it indicates that the position of the placenta is low, and it is a state of placenta previa, which increases the risk of bleeding and miscarriage during pregnancy, and when the general condition is stable, it is necessary to follow doctor’s instructions for dynamic rechecking. However, if there is bleeding, abdominal pain and other symptoms, you need to follow the doctor’s advice to bed rest, and give birth control treatment. If the placenta is low at 13 weeks of pregnancy, it is necessary to pay attention to appropriate rest, avoid exertion and strenuous exercise, and prohibit coitus. With the increase of uterus and the increase of placenta, most of the placenta will be restored to the normal position; however, if the placenta is still low at 32 weeks of pregnancy, it is necessary to strengthen the management of pregnancy, closely monitor the situation of the mother and fetus, and terminate the pregnancy in due course. When the lower edge of the placenta reaches 17mm of the uterine opening at 13 weeks of pregnancy, dynamic observation and rechecking should be conducted under the guidance of the doctor.