Just a loose thought I'd like to share. Would love to hear those who disagree:
Assuming no birth control takes places - the poorest regions have also the highest population growth already and helping them would lead to more of the same, amplifying original problems of those regions creating bottomless well of help.
Thanks for the links. However, it seems that the connection isn't that strong, e.g. from the last article:
"we should not be confident that reducing mortality will always reduce population growth . Methods other than reducing mortality seem more effective in reducing population growth."
and
"the most effective means to achieve decreases in fertility and population growth in Sub-Saharan Africa would be to invest in family planning services and female education."
But except for Sub-Saharan Africa it seems to be working well so I feel kinda convinced :)