A pre-born is inside another human being,(a redundancy, if you are pre-born you are by definition "inside another human being")
possessing Constitutional rights as a US citizen.(Who owns the Constitutional rights? The pre-born or the container, or both?)
The newborn is a separate individual, (And the pre-born is, what exactly then?)
legally declared to be a US citizen. What is the point you are trying to make here? That the container has rights as a US citizen but the pre-born does not? Once you are "delivered" you have "rights" but as long as you are in a container you have none?
Explain please.
You are either playing word games, pretending ignorance (which is dishonest), or unaware of what the 14th Amendment says (which I doubt).