Nope.
The "five years after age 16" language is ancient. My great-grandfather came here from Ireland at age 5 and was naturalized at age 19. The "16+5" rule existed then for naturalization, BUT ONLY IF YOU CAME HERE AFTER AGE 16.
I'm quite sure that a 16-year old US citizen mother living in the US could give birth to "natural born citizens" at any time from 1775 until now.
And, since Obama was born in the State of Hawaii, it's irrelevant anyway. He's as "natural born" as you or I.