What difference would it make if all women in the world, even the poorest, could make decisions about when and how many children to have? 200 million women who want them, don't have access to contraceptives. We don't talk about this inequity because the uncontroversial idea of deciding when to have a child has somehow become shrouded in controversy. And the victims of this paralysis are the poorest people in the world. Melinda Gates talks here about how, working together, we can change this for all women.