I've worked at teaching hospitals for pretty much my whole post-college career, so I generally heave a bit of a sigh when I hear the initials "IRB". IRB's (Institutional Review Board) are set up to protect patients and approve of research, but they also have power to reject proposed studies and cause lots of paperwork. Sometimes though, you need a good reminder of why they were invented.
Apparently, some scientists in the 1940's tried to develop a pain scale based on burning people and rating the pain. Then, to make sure they had a good control, they burned pregnant women while in between contractions.
While it actually wasn't a half bad way of figuring out what their numerical scale should look like, that is just WRONG. As a pregnant women, I can pretty confidently say that anyone coming at me with a flat iron during labor will be kicked. Hard.
Unethical gathering of data is not only not worth it, but also frequently wasted. In the study mentioned above, the data proved useless, as pain is too subjective to be really quantified. After this fiasco, it wouldn't be until 2010 that someone came up with a really workable pain scale.