I used Palmers Coco tummy butter through out my first pregnancy and didn't get any stretch marks. I am currently 33 weeks with our second and using tummy butter again and haven't gotten any... yet! I don't know if it's helping any but I still do it. I know you can't really prevent them if your going to get them there is nothing you can do to prevent them. I think maintaining a healthy weight gain and staying hydrated could help though!