A fetus that is 37 weeks pregnant but is small is considered full term, except that it is called a low-birth-weight baby. A fetus that has reached 37 weeks of gestation is considered to be full term, and is full term from 37 weeks to 42 weeks. However, if the fetus is small, it means that the fetus has not reached the weight and length of a 37-week-old fetus, and the heart, lungs, and senses of the fetus are generally mature, and the small size may be due to malnutrition, developmental delay, etc., so the cause must be clarified. 37 weeks pregnant fetus small must go to the hospital under the guidance of a professional doctor to improve ultrasound examination to clarify the fetus has no developmental delay, if not, it may be the possibility of malnutrition, then supplemental nutrition so that the fetus grows before the birth of the child, and at the same time regularly do a good job of obstetrics and gynaecology work. Pregnant women should eat more food rich in protein during pregnancy, such as eggs, pork lean meat, soy products, milk and so on. It is also necessary to appropriate supplement shrimp, fish, pork liver, oats, walnuts, peanuts and other foods, eat more fresh vegetables and fruits, to ensure that the intake of food nutritionally balanced, to avoid a single nutrition.