How your baby's growing: 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.

See what your baby looks like this week.

How your baby's growing: The network of nerves in your baby's ears is better developed and more sensitive than before. He may now be able to hear both your voice and your partner's as you chat with each other. He's inhaling and exhaling small amounts of amniotic fluid, which is essential for the development of his lungs. These so-called breathing movements are also good practice for when he's born and takes that first gulp of air. And he's continuing to put on baby fat. He now weighs about a pound and two-thirds and measures 14 inches (an English hothouse cucumber) from head to heel. If you're having a boy, his testicles are beginning to descend into his scrotum — a trip that will take about two to three days.

See what your baby looks like this week.

How your baby's growing: Head to heels, your baby now measures about 13 1/2 inches. His weight — a pound and a half — isn't much more than an average rutabaga, but he's beginning to exchange his long, lean look for some baby fat. As he does, his wrinkled skin will begin to smooth out and he'll start to look more and more like a newborn. He's also growing more hair — and if you could see it, you'd now be able to discern its color and texture.

See what your baby looks like this week.

How your baby's growing:Your baby's growing steadily, having gained about 4 ounces since last week. That puts him at just over a pound. Since he's almost a foot long (picture an ear of corn), he cuts a pretty lean figure at this point, but his body is filling out proportionally and he'll soon start to plump up. His brain is also growing quickly now, and his taste buds are continuing to develop. His lungs are developing "branches" of the respiratory "tree" as well as cells that produce surfactant, a substance that will help his air sacs inflate once he hits the outside world. His skin is still thin and translucent, but that will start to change soon.

See what your baby looks like this week.

How your baby's growing: Turn on the radio and sway to the music. With his sense of movement well developed by now, your baby can feel you dance. And now that he's more than 11 inches long and weighs just over a pound (about as much as a large mango), you may be able to see him squirm underneath your clothes. Blood vessels in his lungs are developing to prepare for breathing, and the sounds that your baby's increasingly keen ears pick up are preparing his for entry into the outside world. Loud noises that become familiar now — such as your dog barking or the roar of the vacuum cleaner — probably won't faze him when he hears them outside the womb.

See what your baby looks like this week.