This week, your baby weighs almost 2 pounds (like a head of cauliflower) and is about 14 1/2 inches long with his legs extended. He's sleeping and waking at regular intervals, opening and closing his eyes, and perhaps even sucking his fingers. With more brain tissue developing, your baby's brain is very active now. While his lungs are still immature, they would be capable of functioning — with a lot of medical help — if he were to be born now. Chalk up any tiny rhythmic movements you may be feeling to a case of baby hiccups, which may be common from now on. Each episode usually lasts only a few moments, and they don't bother him, so just relax and enjoy the tickle.