Celeb Post-Baby Bodies: See the Biggest Transformations [PHOTOS]

When it comes to Hollywood, no news is more exciting than when a celeb announces she's expecting! From guessing the gender to waiting for the first pics of the bundle of joy, we can't resist following the pregnancy.

For many of these stars, the pressure is on to get back in shape after giving birth. After hitting the gym for months -- or sometimes even weeks! -- new moms love showing off the product of their hard work. Here's a look at some of the biggest transformations and as a result, unbelievably fit post-baby bodies in Hollywood.

Kim Kardashian

Jessica Simpson

Lily Aldridge

Jenna Dewan-Tatum

Kristen Bell

Snooki

Hilary Duff

Beyonce

Kendra Wilkinson

Amber Rose

Fergie

Tori Spelling

Penelope Cruz

Reese Witherspoon

Mariah Carey

Jessica Alba