Placenta grade I at 38 weeks of pregnancy is a normal condition, indicating basic maturity of the placenta. Clinically, the maturity of the fetus and the placenta can be understood according to the grading of the placenta by ultrasound examination. The placenta is generally divided into four grades, namely 0, Ⅰ, Ⅱ and Ⅲ. Grade Ⅰ indicates that the placenta is basically mature and can meet the supply demand of fetal nutrition. Grade Ⅱ indicates that the placenta is mature and the fetal nutrition and oxygen supply is good, but it will be less than that provided by grade Ⅰ placenta. If it reaches grade III, the placenta is aging and calcified foci appear, which may affect the absorption of fetal nutrients, and there is a possibility of intrauterine hypoxia and distress of the fetus in the process of waiting for delivery, and in serious cases, there is a possibility of fetal death in the uterus. Therefore, after 38 weeks of pregnancy, regular ultrasound examinations should be performed to keep abreast of the fetus and placenta. In addition to the placenta grading, you should also pay attention to the amniotic fluid volume, fetal size and umbilical blood flow. If the amniotic fluid is normal, the fetal size is in accordance with the gestational week, and the umbilical blood flow is normal, then the placenta is considered to be functioning normally and there is no need to worry too much.