Dessí is her fifth husband and this will be her first child with him.
The Surreal Life alum has four sons - Julian (34), Killian (28), Douglas (25), and Raoul (23) - from previous marriages.
Sylvester Stallone's ex-wife shared the news by posing cradling her blossoming baby bump while wearing a white dress, alongside the caption: "Family getting larger".
Vedanta says it has permission to expand in Thoothukudi, activists say no
The company has appealed to government and authorities to ensure safety of our employees, facilities, and surrounding communities. Another man, identified by Indian media as a 23-year-old named Kaliappan, was killed in further protests on Wednesday.
She also took part in the German version of Strictly Come Dancing in 2010 and won the German version of I'm a Celebrity Get Me Out of Here in 2012.
This will be the fourth child for Nielsen, who has been married to her current husband, Mattia Dessi, for more than a decade. In another snap, which showed the 54-year-old relaxing on the sofa with her hand resting on her bump, she said: "Happy time, positive vibes".
This is Brigitte and Mattia Dessi's first kid together. Brigitte wore a pink rose tiara for the beach-side ceremony, with both she and her new husband jumping into the hotel pool immediately after saying "I do".
The blonde beauty was also previously in a relationship with rapper Flavor Flav from 2003 to 2005 and had a one year romance with Arnold Schwarzenegger. "It was all very sudden but we are both very happy".