Fetal weight can be estimated by the uterine height and abdominal circumference of the pregnant woman. The method of calculating fetal weight is uterine height multiplied by abdominal circumference plus 200g, but this is only an approximate range, because the uterine height and abdominal circumference are affected by the thickness of the abdominal wall of the pregnant woman, the volume of amniotic fluid, and whether the head of the fetus is in the pelvis, etc., so according to the uterine height and abdominal circumference is only a rough estimation of the weight of the fetus. It is also necessary to measure the fetal biparietal diameter, head circumference, femur length, etc. to make a comprehensive assessment. If the fetus is estimated to be too large during pregnancy, the pregnant woman should pay attention to controlling her weight and monitoring her blood glucose, so as not to increase her weight too quickly and raise her blood glucose, which may have adverse effects on the fetus. If the fetus is estimated to be small, she should be alert to the possibility of fetal growth restriction and make timely diagnosis and treatment.