Birth certificates in the United States, which are issued by the states, have two different sections, and each section involves different privacy concerns. The first section, the legal record of birth, is always available to the adult whose birth it registers; access by other persons varies widely from state to state, ranging from a short list of specified relatives to the public at large. The second section of the certificate - which records health and medical information about the parents, the birth, and the infant - is used only for data collection and analysis, under regulations that protect the privacy of the registrants and their parents.
Birth Certificates, in Encyclopedia of Privacy (William G. Staples. ed., 2007)