I've got to say, working with residents, one of my biggest pet peeves is when they "conduct the orchestra." If you're an L&D nurse, you probably know what I mean - taking their first two fingers and running/pressing it repeatedly around the lower rim of the perineum as the baby is descending/crowning.
It drives me crazy that they do that. Especially when they do it repeatedly, for hours of pushing. The worst cases of perineal edema have been as a result of that.
The midwives don't ever do that, and yet, the babies still seem to come out okay.