Sexy mama ... A behind-the-scenes shot from <i>Vanity Fair Italia</i> shows Adriana Lima posing for the 2013 Pirelli calendar with her belly on display.

Sexy mama ... A behind-the-scenes shot from Vanity Fair Italia shows Adriana Lima posing for the 2013 Pirelli calendar with her belly on display.

Adriana Lima has become the first pregnant woman to be photographed for the famous Pirelli calendar.

The Brazilian model, already a mum to two-year-old Valentina, has posed for the 2013 edition of the famously raunchy publication with her pregnant belly on show.

For the first time, the Pirelli Calendar 2013 will show a pregnant woman with a visible baby bump 

While she has appeared in it previously, Lima's newest photo is remarkable as it is the first time a noticeable baby bump has been displayed by the world's sexiest calendar.

Model Erin O'Connor posed for a striking portrait for photographer Nick Knight while eight and a half months pregnant. Click for more photos

Bumps on parade: pregnant stars strip down

Model Erin O'Connor posed for a striking portrait for photographer Nick Knight while eight and a half months pregnant. "It’s amazing to be pregnant because instinct is a really powerful force and all you want to do is nourish your baby. The reassurance you get when you see your belly - and other parts - swelling is incredibly reassuring," she told SHOWstudio.

"For the first time, the Pirelli Calendar 2013 will show a pregnant woman, Adriana Lima, with a visible baby bump," reveals a reporter from Vanity Fair Italia, who was on set as it was being shot.

Lima appears in the publication along with models Elisa Sednaoui, Petra Nemcova, Isabeli Fontana, Liya Kebede and Kyleigh Kuhn.

Lima announced her pregnancy in March but has remained quiet on her due date.

AAP

See more in our gallery of pregnant models, or our gallery of stars who have posed naked while pregnant.