Jen,
I'm not sure if it will be bad based on research, but based on what you aim for in a URL (clarity, what the article is about, user experience, descriptive keywords, etc...) the TM Registered may not fit well.
Plus, be careful, your TM (if using symbols) will get changed to () or () in the URL - making it less user friendly to type in (let alone look at)..
Hope this Helps!
Eli Overbey