By the third trimester, fitted knit dresses offer the most effortless way to flatter your figure. Some denim-devoted moms make the switch to the over-the-belly style for added security, while others find they might need to size up once more (especially with more "raw" denim fabrics with lower stretch content). Finally, a longer cardigan or trench helps elongate your figure (while adding a bit of camouflage on the back side).