Week 21

By the end of this week, he'll measure about 7 inches from crown to rump and weigh nearly a pound. Not bad for a little guy who weighed barely an ounce 10 weeks ago! His hearing is developing, and sounds from your conversations can be heard inside the uterus--along with your heartbeat, stomach rumblings, and the pulsing of blood vessels. In fact, the womb is so noisy that it's been compared to an airport runway during takeoff; it's thought that the stimuli prepare the baby for the cacophony of noises, sights, and sounds that will greet him at birth.