Some jackass out there decided to throw this one in the ring and it makes me mad.
You are a nauseous, sweaty blob (well, I was) and the least you should be able to do is pay someone to rub you. Is nothing sacred?
I couldn't find anything really solid on this one. There is the usual "don't do it in your first trimester because you could miscarry" which seems to apply to everything from sneezing to "don't let them touch your feet or you could go into labour". I know plenty of women who would have severed off a toe to go into labour so I'm hoping we would have heard of that trick.
There was also some talk of crazy essential oils that shouldn't be used on you but, all and all, it sounds like if you've got someone willing to rub you down, go for it.
search: massage pregnancy dangers, massage safe during pregnancy