Marisa Miller is no stranger to skimpy swimwear, and on August 6, the Sports Illustrated model showed off her pregnancy curves in a black bikini.
"Thanks so much for all the sweet birthday wishes! Love you all!" the 34-year-old wrote in a Twitter caption. "I had the best day and spent most of it underwater."
PHOTOS: Pregnant models
Miller and her husband, music producer and talent manager Griffin Guess, will welcome a baby boy in December. It will be the first child for both stars, who tied the knot on April 15, 2006.
PHOTOS: Supermodel moms
The former Victoria's Secret Angel -- who has graced more than 80 magazine covers in her career -- first tweeted a photo of her baby bump on August 2.
"This was a month ago at 17 weeks. My belly seems to have doubled since!" Miller wrote. "Had to paddleboard to get to this cave."
VIDEO: Marisa Miller takes Us behind the scenes at Fashion Week
Miller next appears in the movie R.I.P.D., costarring Ryan Reynolds, 35, and Jeff Bridges, 62. She is also the face of Harley Davidson.
This article originally appeared on Usmagazine.com: See Marisa Miller's Pregnant Bikini Body!
It's been 20 years since "Jurassic Park" came out. See what the cast of the movie is up to these days.
Joe Manganiello parties with new love Sofia Vergara and her family in Miami on today's Celebs Gone Social.
Check out some of January Jones' most retro wardrobe choices from over the years.
Britney Spears, Beyonce and more stars share their summer love on social media on today's Celebs Gone Social.
Selena Gomez, Zoe Saldana, and Maggie Gyllenhaal all get an F on this week's Fashion Offenders.
Find out which stars attended Jennifer Lopez's birthday celebration on today's Celebs Gone Social.
See some of the many revealing looks that Kim Kardashian has donned recently.
Find out what happened to the stars of 'Garden State' after they made the hit indie film.
© 2014 Microsoft