I wonder if it was not for the HKS, ANS scheme, LB being persistant and for the Thompsons and Shellys being aware of the pregnancy if Dannielynn would have ever been born.
You're right, conditions were not favorable for Dannielynn ever being born.
I think HKS tried to eliminate DL with drugs when, for whatever reason, ANS didn't abort her. A kid did not fit into any of HKS's plans and now he's stuck with having to fight to keep her to maintain control over the situation.
If ANS didn't initiate the GBT scheme, she perhaps supported it as an insurance policy to justify carrying her child to term.
I think Thompson was important early on because of his role as the 'mark', but LB's dogged (and very public) pursuit of his rights as a father tending to the best interests of his unborn child was the most important factor.