From USA Cycling:
One other note: cyclo-cross is a mass-start race, and according to US Cycling Federation rules, bikes used in mass-start events may not have objects that protrude forward. This means no bar ends in USCF sanctioned cyclo-cross races. Remove them before race day and save yourself an unpleasant surprise at the start line.
http://www.usacycling.org/news/user/story.php?id=1144

I'd tell you to "not crash," but that was me on my back in turn 3 of my first CX. Replacement grips are fairly cheap, may be a good way to keep from getting a circle scar somewhere on your body.

Go have fun, it really is a blast.