Cool. This made me 
(bolding mine)
wtf?
that is pretty cool! it doesn’t suprise me that they smile and cry/frown in the womb…if you’ve ever watched a newborn in a light sleep phase, they will “practice” various facial expression…big grin, sad frown, furrowed brows, everything in between. It’s really cool to watch. Our two month old was “smiling” and sucking her thumb on the warming table, so it makes sense to me that she was doing those things a few days before when she was still in utero. I would say it is a reflex rather than being “happy or sad”, they’re a little young to process emotions in those terms, I think. And they practice swallowing and breathing in utero, so why wouldn’t they practice blinking too?
hill
Dominic was sucking his thumb in the sonogram we took the day we found out he was a boy. 
That image of the baby’s face is so cute. It’s amazing how much better ultrasounds have become in the last few years. I find it hard to see anything in a lot of the regular ultrasound pics I have seen. Someone showed me a pic from her sex-determination ultrasound where it was supposed to be “obvious” it was a boy and I had no clue what I was looking at. However, these new 3-D and 4-D images are awe-inspiring.