I don't know, but to me, a "fat" woman and a "pregnant" woman look nothing alike. A pregnant woman (tends to) be far more feminine, radiating pheromones and so forth. Yes, covered in clothes you can sometimes be mislead, but usually, certainly in bathing suit or less, there's no mistaking who's what. Pregnant women are beautiful. Fat women, well, depends on just how fat, I'm not a fan of stick figures (except in webcomics
) but "morbidly obese" isn't pretty either.
Most "fat" women are ashamed of their body (often wrongly so - most wome who consider themselves "fat" aren't) and hide it; have a bad self image, and radiate a lack of confidence and that sort of things.