Wrong---it requires all "free persons" to be counted.
I am in way over my legal head here, but don't both the concepts of unenumerated rights and the state's interests in protecting the weak rest in part on English Common Law precedent? Third trimester fetuses were on that basis found to be inside the boundaries of protectability by the individual states of the U.S. The other side of that coin is the intrusiveness of trying to criminalize abortion before the third trimester.
As Bork so famously said, we do not have a constitutional right to privacy. But neither do we need that right enumerated to have it, since the Constitution is not addressed to us - it is a list of "thou mays" and "thou shallt nots" addressed to the federal government.