I would be putting in your birthplan that you want to make sure that you have great perenium management during the birth of the baby. By this I mean that you want your support team/midwife to make sure that you are in a position that is conducive to not tearing, like those Feeb suggested as well as supporting the perenium during pushing and if you look like you are going to tear to get you to slow things down and breathe the baby out instead of actually pushing them out.