How your baby's growing:Your growing baby now measures about 4 inches long, crown to rump, and weighs in at about 2 1/2 ounces (about the size of an apple). He's busy moving amniotic fluid through his nose and upper respiratory tract, which helps the primitive air sacs in his lungs begin to develop. His legs are growing longer than his arms now, and he can move all of his joints and limbs. Although his eyelids are still fused shut, he can sense light. If you shine a flashlight at your tummy, for instance, he's likely to move away from the beam. There's not much for your baby to taste at this point, but he is forming taste buds. Finally, if you have an ultrasound this week, you may be able to find out whether your baby's a boy or a girl! (Don't be too disappointed if it remains a mystery, though. Nailing down your baby's sex depends on the clarity of the picture and on your baby's position. He may be modestly curled up or turned in such a way as to "hide the goods.")

See what your baby looks like this week.