It's going to depend on a few things...Does it have a government (i.e. state or county) form number on it? If it is an "official" government form used for recording purposes and is properly completed, it has weight. Even if it is merely a local hospital form, does it have the language of an oath on it? If it does and is signed and properly notarized, it would have the same legal weight as say, an affidavit of the physician attesting to the information on the form. It may not have the full import of an actual Birth Certificate for purposes that specifically require such a document, but it could be instrumental in helping you secure one.
Based on all I now know what I have was just a souvenir from the hospital where I was born.