Usually, the fetal sleep cycle is 20-40 minutes, so it is normal for the fetus to move no less than 3 times per hour. Since the frequency, duration and intensity of fetal movements are different for each fetus and can be influenced by various factors, such as emotion, body mass, placenta position, amniotic fluid volume, etc., there are large individual differences, so it is normal for the total number of fetal movements to increase or decrease by no more than 50% at the same time. However, if there is a significant decrease or increase in fetal movement, or the range of fetal movement exceeds 50%, it may indicate that the fetus has intrauterine hypoxia, and the pregnant woman should go to the hospital for ultrasound or fetal heart monitoring in time. It is recommended that pregnant women should count fetal movements at a fixed time from 28 weeks of pregnancy to delivery. If a pregnant woman has risk factors for intrauterine hypoxia, she can count fetal movements earlier.