HUH?
I think you have "person" mixed up with "citizen."
A human being is a natural person from the instant of conception. Birth has nothing to do with it.
The Supreme Court GRATUITOUSLY asserted that an unborn baby is not a "person within the meaning of the 14th amendment." They reminded Congress that Congress COULD find the opposite, and that the decision in Roe v. Wade would then collapse.
Nothing the Supreme Court does is gratuitous - don't be naive.
Person is defined in the statutes as equivalent to individual and varieties of corporations and government employees. That's just a fact.
A natural person is not a statutory "person." A "person" is an incorporated natural person, ie one with representational authority to, or of, a corporate body, including being an employee of the United States itself.
Birth certificates are only required of incorporated individuals, and establish a presumption of incorporation of a minor. Citizens are individuals who have pledged allegiance to the country. They are different from native-born Americans, who need no declarations or vows to establish their God-given rights under the Constitution.