From Giggle Glow:
This is a time of rapid development for your baby’s brain: he or she is getting smarter by the day! In the meantime, physical growth is slowing down — which may be good news considering how crowded your tummy is probably starting to feel. By now your baby is resting comfortably in the classic fetal position with knees to chest, since there’s not as much room to spread out anymore.
From The Bump:
Baby's going through major brain and nerve development these days. His irises now react to light, and all five senses are in working order. (He won't pick up anything from his nose until after birth, though -- smell is transferred through air, not amniotic fluid.)
From What to Expect:
As far as growth goes, your baby's still on a roll, measuring an impressive 18 inches and weighing in at more than three pounds. At 31 weeks pregnant, you can still expect your baby to gain at least three to five pounds, possibly more, before you two meet.
Your baby's brain is working overtime these days, developing faster than ever. Connections between individual nerve cells are growing at a frenetic clip, and your baby can now perceive information from all five senses. Sure, your baby can't smell anything right now, but that's only because he or she is still submerged in amniotic fluid and needs to be breathing air to get a whiff of anything. Lucky for you — and your baby — yours will be one of the very first scents your baby breathes in, a scent that will quickly become his or her very favorite.
So what's your little dove doing all day while you're busy feathering your nest for his or her arrival? Making faces, hiccupping, swallowing, breathing, pedaling with little hands and feet along your uterine wall, and even sucking his or her thumb. In fact, some babies suck their thumbs so vigorously while in the womb that they're born with a callus on their thumb (what a little sucker!).
From Baby Center:
This week, your baby measures over 16 inches long. He weighs about 3.3 pounds (try carrying four navel oranges) and is heading into a growth spurt. He can turn his head from side to side, and his arms, legs, and body are beginning to plump out as needed fat accumulates underneath his skin. He's probably moving a lot, too, so you may have trouble sleeping because your baby's kicks and somersaults keep you up. Take comfort: All this moving is a sign that your baby is active and healthy.