I didn't take any classes but it didn't matter because I didn't progress past 2cm and I ended up with a c-section.
I had the worst nurse ever, I was having the worst contractions but they weren't being picked up by the monitor and I was crying and in pain and she kept saying "didn't you take any classes?! You're not even in labor! I can't believe you never took any classes!". Then they hooked me up to the internal monitors and she was like "oh wow, your contractions are coming fast and hard, one on top of the other". Um, yeah. No kidding, douchebag.