We are now arriving at "peak child."

Factfulness by Hans Rosling, Ola Rosling, and Anna Rosling Ronnlund.  Page 84.

When I was born in 1948, women on average gave birth to five children each. After 1965 the number started dropping like it never had done before. Over the last 50 years it dropped all the way to the amazingly low world average of just below 2.5.

This dramatic change happened in parallel with all those other improvements I described in the last chapter. As billions of people left extreme poverty, most of them decided to have fewer children. They no longer needed large families for child labor on the small family farm. And they no longer needed extra children as insurance against child mortality. Women and men got educated and started to want better-educated and better-fed children: and having fewer of them was the obvious solution. In practice, that goal was easier to realize thanks to the wonderful blessing of modern contraceptives, which let parents have fewer children without having less sex.

The dramatic drop in babies per woman is expected to continue, as long as more people keep escaping extreme poverty, and more women get educated, and as access to contraceptives and sexual education keeps increasing. Nothing drastic is needed. Just more of what we are already doing. The exact speed of the future drop is not possible to predict exactly. It depends on how fast these changes continue to happen. But in any case, the annual number of births in the world has already stopped increasing, which means that the period of fast population growth will soon be over. We are now arriving at “peak child."