Stretch marks are partly genetic. Everyone's skin varying amounts of elasticity. Some people will get horrible ones from the slightest growth spurt. Others will gain a massive amount of weight in a short time and have only barely noticeable ones. Keeping your skin moisturized will help prevent them to come extent, but there is no way to completely avoid them if you are going to get them.

If you already do have stretch marks, there are no special miracles that will take them away. They do fade on their own after a time however. Keeping your skin moisturized will help with the process. Some will be less noticeable than others, depending on how bad they are.