In some (poverty-stricken) African cultures, number of offspring is an indicator of wealth. I know culture is culture, but often this leads to unnecessary socio-economic problems. In my country, free condoms are easily accessible to any person, rich or poor. Which I think relates to your suggestion? However, for a poor family, another child may be seen as a meal ticket since it will lead to a higher wellfare payout. Even more so if that child is born with a disability (such as fetal alcohol syndrome).

Another problem is that many children end up in orphanages and very few couples prefer adoption over having a child which is biologicaly their own offspring.