I recommend cocoa butter - no stretch marks wt my first and currently 39 wks wt none so far this time around - fingers crossed it stays that way. I understand it's a genetic trait tho, so if your mother had them, you probably will. Good luck!
I took a zinc supplement during my first pregnancy, as recommended by my doctor. I didn't get a single stretch mark, so doing the same again this time!
I heard lots of good things bout bio oil, so I'm using only bio oil. Hopefully it'll works for me. But there's lots of people saying that stretch marks is actually genetics problem, if your mum has it. Then you'll have it. But then again, I don't know how true that that. :/ Can only keep my fingers and toes crossed not to get any. :/