The normal fetal movement at 21 weeks of pregnancy is usually not less than 3-6 times an hour. If it is less than 3 times per hour, you should pay attention to observe the fetal movement carefully, as long as the fetal movement is regular, it is normal. The fetus will move a lot in the mother’s body when it reaches 21 weeks of development, sometimes the fetus will touch the uterine wall with its limbs and even kick its legs, at this time the fetus yawning or turning over will cause fetal movement. Therefore, the frequency of fetal movement is higher at 21 weeks of pregnancy, and pregnant women can clearly feel the fetal movement, and fetal movement is usually around 9-10 in the morning, and more obvious around 3-4 in the afternoon. As the fetus is very small at 21 weeks of pregnancy, the mother-to-be can feel the fetal movement every day, so she does not need to count the number of times. It is easy to increase the tension of pregnant women, which is not conducive to the healthy growth of the fetus.