Your baby now weighs about 4 3/4 pounds and is almost 18 inches long. His fat layers-which he'll need to help regulate his body temperature once he's born-are filling him out, making him more rounder. His skin is also smoother than ever. His central nervous system is maturing and his lungs are continuing to mature as well. If you've been nervous about pre-term labor, you'll be happy to know that babies born between 34 and 37 weeks who have no other health problems, generally do fine. They may need a short stay in the neonatal nursery and may have a few short term health issues, but in the long run, they usually do as well as full-term babies.