Do you want to do four-dimensional after three-level screening?

After the third-level screening, four-dimensional screening is required. This is because the third-level screening mainly looks at whether the fetus has trisomy 21 syndrome, trisomy 18 syndrome and trisomy 13 syndrome. These are generally to check whether the fetus has chromosomal lesions. If there are these lesions, it is necessary to consider whether the development of fetal intelligence is abnormal. Four-dimensional color Doppler ultrasound is mainly to see whether the growth and development of the fetus is normal, for example, there is no hydrocephalus, there is no ventricular septal defect, atrial septal defect and other heart diseases, in addition to can also clearly see the fetal facial expression, this is to do three-level screening can not come out.