From BabyCenter
Your baby's lungs and digestive tract are almost fully developed. While your baby may soon slow up growing in length, (he measures about 15.7 inches/ 40 centimeters from crown to toe by now), he will continue to gain weight until he's born.
This week your baby continues to open and shut his eyes. He can probably see what's going on in utero, distinguish light from dark and even track a light source. If you shine a light on your stomach, your baby may move his head to follow the light or even reach out to touch the moving glow. Some researchers think baring your stomach to light stimulates visual development. But don't expect 20/20 vision when your baby is born - newborns can see a distance of only about 8 to 12 inches/ 20 to 30 centimeters. (Children with normal vision don't reach 20/20 vision until about age 7 to 9.) To complete the picture, your baby now has eyebrows and eyelashes.
A pint and a half/ around a liter of amniotic fluid now surrounds your baby but that volume decreases as he gets bigger and has less room in your uterus. As you and the baby continue to grow, don't be alarmed if you feel breathless, as if you can't get enough air; it's just your uterus pressing against your diaphragm. There is a light at the end of the tunnel though. At about 34 weeks (or just before birth, if this is your second or third pregnancy), your baby's head will move down into your pelvis as the baby gets into the right position for birth. That will make breathing and eating a lot easier.