Apparently your chances of a posterior birth are increased but an anterior placenta doesn't guarantee a posterior birth thank god! My DD1 was full OP vaginal birth with anterior placenta. I however wasn't aware of the positions that can aid in preventing a posterior birth. I recommend researching the positions and exercises to help prevent posterior birth. A posterior birth won't kill you but boy, it is hard hard work. I didn't realize just how hard until I had a perfectly 'normal' birth with DD2 which was an absolute breeze compared to first time around. The exercises are easy and worth it x