The nice thing about boob stretch marks is that, when your breasts go back to normal, the stretch marks are almost non-existant. I didn't even realize my mother had breast stretch marks until she started tanning topless....I remember asking her as a kid, what are those white tiger stripes?
Does that qualify as too much information?
Anyway, I got a few on my breasts last time and they're very faded now. The ones on my tummy, however, look like burn scars.....OY!
....some people say that rubbing oils into your skin (esp. almond and apricot oil, I think) helps. Dr. Sears says it's all genetics, but having extra protein in your diet (vitamin E, too?) can help minimize the number you get. Post-pregnancy, there are A LOT of stretch mark creams (most of the pricey) that can help.