Can four-dimensional ultrasound rule out Down's?

Four dimensional color Doppler ultrasound can not rule out Down's children, because Down's children generally show that there are problems with fetal intellectual development, intellectual development is generally not found in four dimensional color Doppler ultrasound. Four dimensional color Doppler ultrasound can mainly compare the three-dimensional view of the baby's growth and development, especially the face can see whether there are abnormalities in the brain, there is no hydrocephalus and there are no cleft lip, cleft palate such phenomena. In addition, it can also check the heart, see whether the heart is deformed, there is no spine. There were some conditions such as whether the internal organs were extroverted, but he could not rule out Down syndrome.