My purchase was a PinkBlush Olive Draped Maternity/Nursing Maxi Dress. I got it as sort of an impulse buy and immediately started feeling buyer's remorse after reading reviews and people saying to order a size up because they tend to size down. I was even more worried when the next day, a friend took me maternity clothes shopping and I was fitting into Large clothes more than medium.
A few days later, the dress arrived and to my pleasant surprise, it fit perfectly! The material felt very nice and I look and feel very pretty in it. So, it's never a bad idea to get a size up because it's easier to alter clothes down than fill them out, but honestly, it wasn't an issue for me. Wouldn't surprise me if the company saw the reviews and adjusted accordingly.