Any harm in OCR-ing a file multiple times?

We have a large back catalog of CAD drawing files that we recently scanned into Acrobat. I've been able to OCR them in bulk with no problems and it's worked out great so far.

As we move forward we'll be adding about a dozen or so files each week. Ideally, once a month we'd like to go in and OCR the new files. (Unfortunately having a full seat of Acrobat at every desk isn't an option right now, so we can't "OCR as we go.")

My question is, will re-OCR-ing a file affect it's quality? If I were to OCR a file several times over the course of the year would I have any problems? Is there any problems with quality or file size?

Selecting one folder to OCR and letting it run overnight is obviously much easier than trying to pick out all of the new files, but at the same time I don't want to damage our original scans.

Anyone have any thoughts or experience on the matter?

Thanks,
Eric