In an interview with British radio, the 43-year-old former supermodel turned singer says the pregnancy is "something very banal" - even if "great news" for her personally.
"I'm superstitious, so yes, I've been very careful," she told BBC. "But there isn't much to say. So many women are expecting children and giving birth, and it's so uninteresting for French people."
President Nicolas Sarkozy, who is potentially facing a tough campaign in France's presidential election next spring, married Bruni in 2008, less than a year after he took office. She has a son from a prior relationship, and he has three sons from two previous marriages.
Bruni-Sarkozy said "playing guitar and touring is what I miss most," and she didn't discuss next year's presidential election in excerpts posted on the BBC Web site Monday. The full interview is to be aired Tuesday.
In a possible hint that being first lady isn't her favorite job, Bruni-Sarkozy was quoted as saying: "My dream life is just to go back to my job full-time and be with my family. You know, regular dreams, common dreams that everyone has."
The shy brunette, who once told an interviewer that her "gut reactions" are on the political left, also confided about what made her fall for Sarkozy, a brash and determined conservative: His knowledge of gardening.
"When I met him, walking around the garden in the (presidential Elysee Palace), he keeps giving me all these flowers' names," she said. "He knows all the Latin names, all these details about tulips and roses.
"I said to myself: 'My God, I must marry this man, he's the president and he knows everything about flowers as well. This is incredible."'
Bruni-Sarkozy was speaking to guest host Christine Ockrent, a well-known journalist in France who recently was a top manager at France 24 TV. The report didn't say when the interview took place. Ockrent is married to Bernard Kouchner, who served as Sarkozy's foreign minister for almost 3-1/2 years, and was said to be a longtime Bruni-Sarkozy friend.
The Italian-born first lady also noted that her child is set to become the first baby at the Elysee Palace: "I guess it's the modern world going into the French Republic, which is not bad."