That's really become commonplace, hasn't it? I heard an anesthesiologist quoted to the effect that if a gal has a tattoo in that area, she'd better hope she never needs an epidural. Something to do with more likelihood for infection, as well as the doctor not knowing the makeup of the ink.
Makes sense, and I'm kinda surprised you don't hear this more often.
Snopes.com has more information here: Suffer to Be Beautiful.
It sounds like what you mention is an urban legend for the most part.
I'm not a huge fan of (most) tattoos on women -- any woman (or guy) who wants to look better would be better off getting some exercise instead of whatever else they do to look attractive.