What Is a 3D Ultrasound?
A 3D ultrasound takes multiple 2D images from different angles and stitches them together to create a three-dimensional still image. The result is the classic amber/golden face image you've probably seen on social media — it looks like a clay sculpture or wax figure of your baby's face.
What Is a 4D Ultrasound?
A 4D ultrasound is simply a 3D ultrasound in real time. The "4th dimension" is time — so instead of a still image, you see a live video of your baby moving, yawning, or sucking their thumb. Many clinics charge extra for a 4D session.
3D vs 4D: Which Should You Get?
For AI baby portrait generation, both produce equal results — what matters is the still image quality, not motion. A single frame captured from a 4D session, or a high-quality 3D image, both work well with AI tools like FirstGlimpse AI.
| Feature | 3D Ultrasound | 4D Ultrasound |
|---|---|---|
| Still image | ✅ Yes | ✅ Yes (captured frame) |
| Real-time video | ❌ No | ✅ Yes |
| AI portrait compatible | ✅ Yes | ✅ Yes |
| Average cost | Lower | Higher |
| Best for | Portrait generation | Watching baby move |
When to Get Your Scan
For the clearest facial detail, most sonographers recommend a 28–32 week scan for 3D/4D imaging. Earlier than 28 weeks, the baby has less subcutaneous fat, which makes the face look more skeletal. After 34 weeks, the baby's head may be deep in the pelvis, making the face harder to image.
What Type Does FirstGlimpse AI Need?
Any 3D or 4D ultrasound still image works. Just make sure:
Upload your best face-on 3D frame and the AI will do the rest.