From the research I've done they are almost never necessary. They are not necessary for vacuum or forceps deliveries, though often still used for those. They do not 'prevent tears' - what a ridiculous idea! - but in fact dramatically increase your likelihood of having a bad tear as well as PPs have mentioned. Shoulder dystocia is usually resolved by positional changes, and if necessary a HCP can get their fingers in to manoeuvre baby without cutting the perineum. And yes, I would think the adrenaline of being told you need to get your baby out *now* would be sufficient in many cases to get a distressed baby out quickly.
And as PPs have mentioned, although episiotomies are convenient for HCPs - both to cut a few minutes off a pushing stage if they're feeling impatient, and to sew back up, that does not mean they're better for the mom - generally the opposite. I had a very large one, and still have problems with it over 2 years later. My mom has trouble with hers over 30 years after she had me. We can't know for sure, but it's a fair bet that we would have recovered much better from a *potential* tear, since there was no reason to believe that we would even have torn for certain.
And as PPs have mentioned, although episiotomies are convenient for HCPs - both to cut a few minutes off a pushing stage if they're feeling impatient, and to sew back up, that does not mean they're better for the mom - generally the opposite. I had a very large one, and still have problems with it over 2 years later. My mom has trouble with hers over 30 years after she had me. We can't know for sure, but it's a fair bet that we would have recovered much better from a *potential* tear, since there was no reason to believe that we would even have torn for certain.
