Alessandra Ambrosio Gave Birth to a Baby Boy Yesterday [Updated]

COSTA MESA, CA - NOVEMBER 29: Model Alessandra Ambrosio arrives at the 2011 Victoria's Secret Fashion Show Viewing Party at the Samueli Theater, Segerstrom Center for the Arts on November 29, 2011 in Costa Mesa, California. (Photo by Frazer Harrison/Getty Images) Photo: Frazer Harrison/2011 Getty Images

Her fiancé Jamie Mazur confirmed the good news on Twitter, writing, "Welcome my son, can't wait to show u around this crazy place." The pair already has one daughter, 3-year-old Anja. Update: The couple has named their new baby Noah Phoenix.