A nursery might appear to be flawless, but the slightest leak can penetrate (the bed base) and there it lies for days undetected. That sleep-issue-in-your-bed problem is what prompts a lot of parents to reconsider their arrangement. The mess in the present is irritating, but it's the prolonged dampness that you really need to worry about. Over time, trapped moisture inside can cause staining, a stale odor, even with new sheets.