Occam's razor in this case is closer to a Schick twin-blade...the baby-momma could not have conferred NBC due to her age. The bigamist father, BHO1, was not a US citizen, so bingo-bingo, no NBC for Baby-Barry on both counts. BUT, none of us have "standing", so the razor is rusty.
Depends on where he was born.
As I understand the law on the books at the time of Obama's birth, Stanley Ann would had to have given birth to Barry on US soil to confer citizenship on him.
If she gave birth to him outside the territorial US, the law says she was not of sufficient age to confer US citizenship on him.
If she gave birth to him outside the US, he's not even a US citizen, much less, a Natural Born US Citizen.