It is generally recommended that the best time to do 4D ultrasound is from 6 months to 6 and a half months of gestational age. At this time, the baby’s development is more perfect and the ultrasound can perfectly display the structure of the baby’s heart in one plane, which can increase the detection rate of malformations. It is recommended that on the day of the 4D ultrasound, the mother wears loose and easy-to-move clothes and eats a good breakfast to the hospital. If she does not eat, the baby will not have the strength to move around and will not cooperate well when she needs the baby to cooperate with the body position. You can print photos of your baby or take a short video of your baby for the 4D ultrasound, and pregnant mothers can choose according to their situation.