My last two were OP births and they were both vaginal. first OP birth was 4.5hrs, induced with syncto with minor shoulder dystocia and I had a 2nd deg tear. 2nd OP birth was 6hrs with shoulder dystocia and only a graze. He actually got into a position at the end where his head was looking over his right shoulder, suggesting that he was still OP, but his body had turned so that his back was along my left side, so he was sideways, hence the shoulder dystocia. Neither time did they use instruments.