Birth control, preferably in the form of mass sterilizations the humane thing to do for every “developing” nation.
It will give those lands the best shot at eradicating poverty and hunger.
No Christian or Conservative should support such a thing. What they need are real property rights. The education of women also has a direct effect on birth rates. Unfortunately, both come from deeply-held cultural attributes about how a society views wealth, individual rights, and the role of women. I doubt Africa will achieve it.
Historical evidence suggests that reducing infant and child mortality stabilizes populations.
When parents lose a child they are likely to have many more as replacements.
Culture and IQ are tougher nuts to crack. Its not up to the west to save Africa from itself.