Generally, slight fetal movements will occur at 18 weeks of pregnancy, but each pregnant woman is different and it is possible that she may not notice significant fetal movements. As the fetus grows and develops, pregnant women may gradually feel the fetal movement from 18-20 weeks. The initial fetal movement is gentle, like a butterfly flapping its wings, but as the pregnancy progresses, the fetal movement will become more pronounced and regular. After the appearance of fetal movement, pregnant women can judge the growth and development of the fetus by counting the number of fetal movements. In other words, the number of fetal movements will be counted for one hour in the morning, midday and evening, and the number of consecutive fetal movements will be counted as one, and the number of fetal movements accumulated in three hours will be multiplied by four to be the number of fetal movements in 12 hours. Generally, the number of fetal movements per hour is 3-5 times, and the number of fetal movements in 12 hours fluctuates about 30-40 times. In addition, the pregnant woman’s tension, overwork, activity, etc. may cause changes in fetal movement. Pregnant women can observe during the same period of time to determine the pattern of fetal movement. If the pregnant woman does not feel the obvious fetal movement, it may be due to the pregnant woman’s abdominal fat is too thick or the new mother is not clear about the fetal movement feeling, fetal development abnormalities and other factors, need to further improve the ultrasound examination to clarify the fetal development, in order to ensure the normal growth and development of the fetus.