You can book your 3D sonogram session as early as 8 weeks. However, each trimester will bring you a completely different view of 3d 4d baby imaging. Earlier in your pregnancy, with 3D pregnancy scan, you may be able to see the baby’s whole body and all the movements in one frame. However, while your baby is very active, before 20 weeks the facial features aren’t yet developed, so it is difficult to see who your baby looks like! To see the face better, it’s best to schedule your 4D ultrasound around 25-28 weeks. Keep in mind also, that waiting past 30 weeks might reduce the clarity of the pictures because babies tend to cover more as they grow bigger.