On Saturday the eight month pregnant beauty celebrated her pregnancy in Florianopolis, Brazil wearing a flowy crop top and pleated long skirt that showed off her very big belly.
Ambrosio was joined by friends who took turns painting her stomach with peace signs, happy faces and hearts according to Vogue Brasil.
She even tweeted a photo of herself looking stunning as she posed with her big bump on the beach:
Just posted a photo instagr.am/p/KQcNNnKbkD/— Alessandra Ambrosio (@AngelAlessandra) May 5, 2012
This will be Ambrosio's second child and first son; she currently has a daughter, Anja, with her fiance Jamie Mazur.
Click through our slideshow to see other model moms and head over to Vogue Brasil to see more photos from Alessandra's big day.
Daughter Anja Mazur (WireImage photo)
Daughter Leila Rose (Getty photo)
Daughters Sara Kate and Gerogia Tatom (Getty photo)
Daughter Rumi (Getty photo)
Son Jack and daughters Alexa Ray and Sailor (FilmMagic photo)
Son Augie (Getty photo)
Daughter Lily (Getty photo)
Daughter Grace (Getty photo)
Daughter Ever Gabo (Getty photo)
Daughter Zulekha (Getty photo)
Daughter Vida (FilmMagic photo)
Son Henry and daughter Leni (Getty photo)
Daughters Charlie and Dolly (FilmMagic photo)
Archie Dury and son Tobin Jack (Getty photo)
Son Presley Walker and daugther Kaya Jordan Gerber (FilmMagic photo)
Daughter Lila (WireImage photo)
Daughter Clementine and son Caspar (FilmMagic photo)