Fifty years ago, the average woman in Botswana had seven children . Now she will have fewer than three. Enabling women to control their fertility has had huge ramifications for their health, education and employment – could President Trump’s ‘ global gag rule ’ threaten this? Nicola Davis travels to Botswana to investigate

Fifty years ago, the average woman in Botswana had seven children. Now she will have fewer than three. This marks one of the dramatic reductions in fertility in the world and could hold lessons for addressing one of our biggest challenges – how to grapple with soaring world population?

The world’s population is on track to hit 8 billion in 2023, and almost 10 billion by 2050. Sub-Saharan Africa is set to grow faster than anywhere: there were 1 billion Africans in 2010, a number projected to grow to 2.5 billion by 2050.

Some have warned that this growth risks “driving civilisation over the edge”. This is controversial, given that it is rich countries, not poor, that are consuming the majority of the world’s resources.

Nicola Davis travels to Botswana to see how empowering women has not only reduced fertility rates but has also had enormous ramifications for women’s health, education and employment, as well as knock-on effects for society and the economy. And, she asks, could President Trump’s “global gag rule” threaten this progress?