4D refers to four-dimensional ultrasound, four-dimensional ultrasound baby does not cooperate, can be slightly adjusted after another, or go back to rest for a day or two before redoing four-dimensional ultrasound. Four-dimensional ultrasound is an important means of diagnosing fetal malformations, as its sensitivity, specificity, and accuracy are higher than other types of ultrasound, it can provide richer diagnostic information, and at the same time, it can continuously display the condition of the fetus in the uterus, and it is non-invasive and can be repeated. If the baby is not cooperative during the 4D ultrasound, it can lead to inaccurate 4D ultrasound results. It is suggested that you can go out and move around for half an hour, or eat some food in moderation to raise the blood glucose level in the blood, or you can adjust the position of the baby in the belly or the state of activity, and then repeat the process. If the repeated examination fails, you can choose to repeat the examination after a day or two. Four-dimensional ultrasound has important clinical value in diagnosing fetal morphological and structural malformations and reducing birth defects, so be sure to actively cooperate with your doctor.