Like regular ultrasounds3D and 4D ultrasounds use sound waves to create an image of your baby in your womb. What’s different is that 3D ultrasounds create a three-dimensional image of your baby, while 4D ultrasounds create a live video effect, like a movie — you can watch your baby smile or yawn.Jul 2, 2018
3D/4D Ultrasound – WebMD › baby › 3d-4d-ultrasound