How do they do a 4d ultrasound?

Question

I'm having my gender reveal today and I was wondering if there is any difference in the 2d and 4d ultrasound ?

Answer

I just had one a couple days ago at 20 weeks. We could clearly see her smile, suckered her thumb, and could tell she looks very much like her sisters did as babies. Big difference over the 2d.  I seen someone say 30 weeks but unless you are high risk the 20 week anatomy scan will most likely be the last.

Answer

All they do it push a button on the regular ultrasound machine and it switches from 2d to 4d, then you can see facial features etc instead of just a profile. Here I thought it was some fancy machine and that's why they charge so much to do it, nope its literally a button.

Answer

It's better to wait till 30 weeks cause the baby's face is fully form for the 4d

Answer

4d let's you see your baby in live vivid form you can see if they smiling and moving and you get better idea what they look like.