Carla, 43, looked remarkably trim and toned as she waded in the sea and relaxed on the sand in her tiny taupe two piece.
Her diminutive husband, Nicolas, 56, cut a slightly less alluring figure in baggy navy shorts, pulled well up to hide his own bulging belly.
The couple are enjoying a summer holiday in the South of France. Their first child together is believed to be due in October.
The baby will be her first with President Sarkozy, although she has a son, Aurélien Enthoven, who was born in 2001 during her relationship with philosophy professor, Raphaël Enthoven.
It was previously rumoured that the Sarkozys were expecting twins - but judging by the size of her bump at six months, we rather doubt it.
Did you wear a bikini when pregnant? Or strictly a one-piece?