A small amount of calcification in two grades of the placenta at 37+4 is not normal, suggesting that the placenta is already progressing towards aging, and the intrauterine condition of the fetus should be closely observed to prevent intrauterine hypoxia caused by aging of the placenta. The maturity of the placenta can be divided into four grades, i.e. grade 0, grade I, grade II and grade III. A placenta that has reached grade II or above is considered mature, while grade III is a sign of over-ripening and aging of the placenta. Before full-term delivery, placenta grade II is the most suitable. grade II mature placenta has good oxygen-carrying capacity and can provide abundant nutrients for the fetus. when the placenta develops from grade II to grade III, calcified foci of varying degrees will appear in obstetric ultrasound, and the oxygen-carrying capacity of the placenta will decrease, which will lead to intrauterine hypoxia or developmental delay of the fetus, and termination of pregnancy will be needed if necessary. Pregnancy 37 + 4 belongs to the full-term pregnancy, during this period of delivery placenta II a small amount of calcification, indicating that the placenta has begun to age, need to pay close attention to the development of the fetus in the uterus, once the occurrence of intrauterine hypoxia, should be timely delivery or cesarean section.