A 37 week fetus on the small side for one week does not necessarily have a low birth weight. 37 weeks fetus is small for one week, the time of birth of the fetus is still uncertain, through the growth of a few weeks, it may be born in the normal range of weight, or it may still be born with a light weight, or it may be born with a heavy weight through growth. Moreover, this result is checked by ultrasound, and there will be errors with the weight of the fetus itself, so it can only be used as a reference. If a pregnant woman finds that her fetus grows smaller than the normal gestational week during her maternity checkup, she can undergo further examination to see if the pregnant woman has hypertensive disorders of pregnancy, malnutrition, etc. If it is due to a disease, it needs to be timely treated for the cause under the guidance of the doctor. If the pregnant woman and the fetus are otherwise normal, nutrition can be strengthened and dynamic observation can be made.