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Alessandra Ambrosio

Just six days before giving birth to her son, Noah, in May 2012, Alessandra Ambrosio shared this photo during a hiking trip, in which she's posing in sweatpants and a sports bra atop a cliff. Ya know — your typical workout outfit. (Well, she is a Victoria's Secret model.)

Pregnant Celebs Bare Their Bumps

Yahoo Celebrity

Remember when it was a really big deal that Demi Moore showed off her baby bump on the cover of Vanity Fair? Well, we've come a looong way since 1991, folks. Today, celebrity moms-to-be sharing bare belly shots is the new normal. And they don't need a fancy photo shoot to do it — just a camera phone and a Twitter app. Check out these pregnancy selfies shared by the stars...