Pre-pregnancy I am 118-122 lbs, 54 and a size small in underwear. I got medium as I have grown with pregnancy and the fit is right on par. They are also soft and cute which I like. One thing that is weird like others said is that the liner in the underwear doesnt match up to where it needs to be- its set back some. If the company fixed this they would be perfect. I have of course only washed them once before wearing so unsure what the wear and tear is like.