It may sound like an annoying rule that some hospital dreamed up just to make your life more difficult, but taking your piercings out before surgery is just plain smart. Piercings in general are not dangerous, and pose minimal risk for infection, but you still need to take them out before a procedure. Plan on putting spacers in prior to your procedure so you don't piercings don't close.
Same with regular jewelry, take it off before surgery.
If you are having imagine studies (xray, MRI, CT scans) of a part that is pierced, same thing goes... take out the piercing.
Wondering why you need to take off your jewelry, remove your piercings and leave them at home? Check out this article: Why You Should Remove Your Jewelry and Piercings Before Surgery