4 weeks of pregnancy is a gestational month, therefore, 39 weeks means 9 months plus 3 weeks of fetus, at this time the pregnant woman reaches late pregnancy and is about to enter the expected date of delivery, while the fetus already belongs to the full-term fetus, all systems have been well developed, and there is always the possibility of delivery. The size of the fetus at 39 weeks of gestation is generally between 6-7 pounds, the biparietal diameter is generally above 9cm, the femur length can reach about 7.3cm, the fetus is mature, so 39 weeks of gestation is the time of elective cesarean section for women who choose to deliver by cesarean section. If a pregnant woman chooses to deliver by cesarean section, she should prepare her maternity bag, get ready for labor and observe her body condition at any time. If she sees redness, irregular contractions, amniotic fluid breaking out and other conditions, it means she is about to deliver and should go to the hospital for examination in time. In addition, pregnant women at 39 weeks can do more exercise, such as climbing stairs, deep breathing exercises, etc., to avoid strenuous exercise and fright, which will help to deliver quickly later. You should pay attention to a balanced diet, replenish the vitamins, trace elements, minerals and dietary fiber required by your body, and avoid eating cold or spicy foods to prevent adverse effects on labor.