There is a really good book called 'the thinking womens guide to a better birth' and it has alot of interesting info about episiotomies. Basically the theory in the book is that perineums are like fabric, you can stretch it really really far until it tears, but put a cut in it with some scissors and it will just continue to tear along that line very easily. I had a c/s with my last birth so don't have personal experience, but the women I know that ended up with the worst tears always had episiotomies first. So personally I am avoiding it.