"The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people."
Are babies people?
Is the right to life of innocents alienable, or unalienable?
Every reference in the Constitution to individulals that I can find starts from birth - from the calculation of a person's age for purposes of military service or holding public office to questions of country of citizenship. All predicated on time or place of birth. They made no reference to time or place of conception, and make no recognition of the person before birth.
If there's any reference there to recognition of "personhood" prior to birth, I'll be happy to consider it if you can show me where it is.