Pregnant women who can’t observe the face of the fetus when doing 4D ultrasound can do activities, such as walking or climbing stairs, etc. They can also get some energy to increase the probability of fetal movement, and it is possible to observe the face of the fetus. Pregnant women can go out and do activities, such as walking or climbing stairs, if they can’t observe the face of the fetus during the 4D ultrasound. Because the fetal movement will also increase when the pregnant woman is exercising and the fetus is moving, there is a probability that the face of the fetus can be observed during the 4D ultrasound. In addition, the fetus does not like to move when the pregnant woman is hungry, so the pregnant woman can add energy appropriately to increase the fetal movement. When doing 4D ultrasound, pregnant women can choose the time to do the ultrasound according to the pattern of fetal movement. In this way, the probability of observing the face of the fetus will increase when the fetal movement increases.