Poverty is not a choice but dictated by economic circumstances. If you want to "fix" humanity, it's not by taking away a universal right from humans, but by making sure that their needs are are taken care of.
But when? Pre-conception seems like the best choice and yep, they have $$$. Oh, no, month 2 of the pregnancy has a complication which wipes out $$ of their money. Still, good to go. Oh no, there's a birth complication and that's another $$ wiped out. Basically on the edge of financial viability now - do you take the baby away? Then there's, say, a global economic meltdown and our unlucky parents are now wildly underwater - do you take the baby away? Or the landlord decides to jack up the rent or sell the building or ...
It's a nice idea but ultimately unworkable unless you can predict the future.
There is something very visceral that comes out of people when you suggest that procreation should perhaps not be a universal right. And don't get me wrong, I think parenthood is integral to a society, but we're broken atm and need to get to a place where we have an upward trajectory.