Understanding the Difference Between 2D, 3D and 4D Ultrasounds Explore the differences between 2D, 3D, and 4D ultrasound pregnancy scans and learn when doctors recommend 3D and 4D ultrasounds and if and when parents can request them. https://isaiminia.com/2d-3d-or-4d-ultrasound-what-expecting-parents-should-know/