Orbit isn’t infinity, but it’s above national airspace. That precedent was set with Sputnik. It’s what allows spy satellites to fly without being shot down. It’s a pointless question. If a woman bears a child in orbit, its citizenship would be based on hers, unless it was aboard a sovereign facility of some sort (ISS wouldn’t count as US territory, due to its international nature).
You can orbit at any altitude in a thought experiment, which is what this is. Nitpicking about the irrelevant parameters of the thought experiment is just dodging the question. For those of you who simply cannot get beyond forcing an idea into a real world scenario, just think of it as a plane flying over the country in route to another country.