Didn't do it at all. Had a very long labour, ending in 2.5 hours of pushing and forceps. No episiotomy - two teeny tiny stitches with an 8lb 10oz baby.

I asked my midwife in one of my appointments and she reckons it's a waste of time and it's all about how stretchy your skin is naturally eg. some people get stretchmarks and others don't. I didn't get any stretchmarks so I think my skin is naturally quite stretchy.

But if it makes you feel more prepared, then go for it.