What might be found on a birth record after 1910?

These records may contain not only the full name of the recorded individual, but also the maiden name of the mother and her age; the father's full name and age; whether they are citizens of the United States or where they are residents; if the mother had other children born to her, and if so, the date, time, place of the birth; and often a witness who may be a relative.

What might be found on a birth record before 1910?