Is the four-dimensional passage rate high when NT is normal?

If NT is normal, the rate of 4D ultrasound is relatively high, but these are two different examination items. NT refers to the thickness of the transparent layer of the fetal neck measured at 11-13+6 weeks of pregnancy. If NT is too thick, greater than 3.0mm, the fetus has Down syndrome or congenital heart disease. Further Down screening, non-invasive DNA screening or amniotic fluid puncture are needed to confirm the diagnosis. Four-dimensional color Doppler ultrasound refers to the systematic examination of fetal malformations at 22-28 weeks, which is to dynamically monitor whether there are structural abnormalities in the fetal head, internal organs, limbs and heart. The screening items during pregnancy must be combined with each other in order to eliminate fetal malformations to the maximum extent and achieve eugenics.