I'd say in the West/ Mediterranean Basin, human sacrifice was doomed when the Romans outlawed it, if not later when Christianity and Islam rose to prominence.
In the East, it certainly went out with the rise of religions like Buddhism.
The Americas... well, I think we all know how that happened.
So, I'd say the logical conclusion is to prevent the widespread extinction of human sacrifice, we need to snuff out Buddhism. Without Buddhism, there is no Roman Empire (affects the Diadochi, intern affecting the rise of Rome), which means no Christianity or Islam.
Though Hellenistic states (and Persian? Did the Persians practice human sacrifice?) would outlaw the practice, I think we would still see it in Western/Northern Europe, Africa, and Arabia.