I'm of the opinion that humanity (in the west) is currently at an important place in evolution. The evolutionary pressure is so high that we will evolve a caste of giga-breeders that will take full advantage of the fact that a modern nation won't let children starve. This will either happen via religiosity or just strong urge to breed. Sadly at the moment, stronger breeders are also correlated with having worse intelligence, so while birthrates will rise again in the next 200 years, they will explode exponentially and the society will collapse spectacularly as it will become an overpopulated hellhole of idiots. At least during that collapse, intelligence will be strongly selected for, but hard to say what happens after that.