Hate to break it, but it's no myth that moms-to-be sometimes go up as much as a full size during pregnancy. Don’t freak out just yet, though; the good news is, not all women experience this particular side effect, so there’s still a chance you won’t either. The size change is usually due to how much fluid you retain and how much you swell while pregnant. Also, if you've gained a lot of weight during your pregnancy, some of it might be going to your feet (hey, no place is safe!). But calm yourself with this thought: After you give birth, the swelling will likely go down and your feet will shrink to their normal size — especially once you get back to your prebaby weight. If not, it's just an excuse to buy new shoes.