It's true, but I found the epidural slowed my labour. I got one at 8cm with my daughter, but they didn't know I was 8cm already. They checked after they gave it to me. They said had they known, they'd never have given it to me.
But I did throw up...and my daughter came out too quickly, and I ended up with 86 stitches. Vomitting during the pushing stage pushes all the muscles necessary for pushing a baby out, and if you push too hard, which happens when vomitting during labour, you'll end up with a massive tear like I did. As a result, I suffer from coital incontinence now and surgery is the only way to repair that issue. I can't have an orgasm without peeing everywhere, or I have to stop before climax, pee, and then work up again.
Trust me, you don't want to suffer through that.
But the epidural at 8cm slowed my labour. It was an hour and a half after I got it than my daughter was finally born. With my son, I didn't get it. They just broke my water at 7cm, and 3 minutes later, I was 10cm, and 12 minutes after that, my son was born. Had I known, I'd have never gotten the epidural. I don't plan on it this time either.