The fetus is about 40cm long, 32cm long at the top and rump, weighing about 1700g, with an average biparietal diameter of 8.17±0.65cm, an average abdominal circumference of 26.20±2.33cm and a femur length of 6.43±0.49cm. At this time, the fetus has deep red skin and is still wrinkled, its body development is complete and its nervous system is beginning to develop. The fetus will respond to strong external sounds. However, there are individual differences in the development of each fetus, so it is important to perform regular maternity examinations to determine whether the fetus is normal according to its own development. If the fetus is small in the 8th month of pregnancy, the range of smallness is <2 weeks, which is normal. If the pregnant woman has delayed menstruation and ovulation, it may lead to late formation of the fertilized egg and thus late development of the embryo, so the pregnant woman does not need to be overly anxious and regular maternity checkups are sufficient. If the fetus is smaller than 2 weeks, it is possible that the lack of nutrition during pregnancy has led to severe malnutrition, which requires timely supplementation to ensure adequate protein and other nutritional intake. In addition, it is necessary to exclude chromosomal abnormalities of the fetus, and if necessary, amniocentesis or cord blood puncture is needed. If the fetus is large, you need to control the diet in the second trimester, try not to eat too much nutritious food, you can eat more fresh vegetables and fruits, and move properly to avoid the fetus growing too fast.