From Babycenter:

"At around 4 inches long, crown to rump, your baby now weighs about 2 1/2 ounces. He's busy inhaling and exhaling amniotic fluid, which will help the air sacs in his lungs develop. His legs are growing longer than his arms now, and he can move all his joints and limbs. That means his hands are more functional, too. Sweat glands are appearing, and although his eyelids are fused shut, he can sense light. If you were to shine a flashlight at your tummy, he'd be likely to move away from the beam."