There's quite a bit of info out there on Stretch mark treatment. They are basically treated just the way scars are. It takes time but with good care they do fade.
Prevention is based around keeping skin well moisturized and malleable, cocoa butter, beeswax ect....
Treatment can include vitamin e and d for healing, alpha hydroxy and salycilic acid that exfoliate, lighten and soften the texture. They remove dead skin and promote skin renewal, I've used these for stretch marks, scars and once for lemon stains on my skin with great results.
I've used Eucerin and Walgreens brand.
There are also natural home remedies out there but I haven't tried them.