Four-dimensional is also known as four-dimensional ultrasound, four-dimensional ultrasound when the baby has been lying on his back can not be photographed face can be changed position, appropriate food, fetal education, change the examination time. 1. change position: four-dimensional ultrasound baby has been lying down can be appropriate to change position, to the left or right lateral position, can also be appropriate to get out of bed to walk or climb stairs, to see whether the fetus will change position. 2. Appropriate eating: 4D ultrasound baby has been lying down can be appropriate eating, through swallowing, chewing and other actions to promote gastrointestinal activity, strengthen the fetal movement after the body position will change. 3. Fetal education: usually have to the fetus for fetal education pregnant women, the fetus in the uterus lying on the ground inactivity can be appropriate fetal education, the fetus may also change the body position. 4. Change the examination time: through the above methods the fetus has been inactive, you can go back to the hospital again after 1-2 days to check. After pregnancy to do four-dimensional ultrasound examination, to be able to timely understand the fetal development in the uterus whether there are abnormalities.