How big is the pdf? If it exceeds Word size limitation, maybe you can split the pdf in chunks small enough to fit under the limit.
Preview can easily create these: select some pages in the sidebar, command-C to Copy, Command-N to "new from clipboard".
FWIW, I just tried this on a fairly math rich pdf, and was surprised that the result was pretty decent (not LaTeX good, of course, but quite acceptable).
EDIT: I have to qualify my previous comment. It looked ok, but then I realized that many of the formulas were just taken as images, not editable anymore. Not that I'd use this myself but I can see how it can be useful to some.