Four-dimensional is also known as four-dimensional ultrasound, do four-dimensional ultrasound baby does not cooperate can not indicate whether the smart or stupid, this is no scientific basis. If the baby is not cooperating with the four-dimensional color ultrasound, it may be that the baby is sleeping and the examination is not clear if the position is not appropriate, which does not indicate whether the baby is smart or stupid. It is recommended to go to the hospital to do four-dimensional ultrasound examination in the 22-28 weeks of pregnancy, at this time the development of all aspects of the fetus is basically perfect, the amount of amniotic fluid in the uterus is more adequate, the fetus in the uterus of the mobility of the better, the results of the examination will be more accurate. The baby does not cooperate with the examination can be appropriate to get out of bed activities, eat some food, climb stairs, fetal education and other behaviors, so that the fetus in the uterus to move, change the position of the four-dimensional ultrasound is easier to pass. After pregnancy through the pregnancy test can not determine whether the fetus is smart or stupid, this to be able to judge after birth.