Grace, you would think it is a very deep thought provoking question, but looking at the over 7 billion plus world population. One can conclude that family planning didn't enter their picture. It is apparently, the exception than the rule to have valid reasons and a well thought out plan for procreating, much less for the family.
When I see pictures of all those really poor people in the 3rd world countries, I don't see they put in any thought for raising a child. The child is skin and bones with a cloud of flies around them. There is little water, food, or even clothes, yet these people didn't care.
Places like China have tried to modulate their population but it has been difficult. The other factor in this question is the ubiquitous use of illegal drugs, alcohol and unprotected sex even and maybe especially in the so called wealthy loins of the United States. The US has homeless, jobless and sick people that could have been the product of sex drive of two people rather than the thought process of intelligence from two brains.
So, I don't think that there is much thought in this subject that really demands a considerable amount of thought and planning.
Look at the Roe v Wade Abortion versus pro life issue. This issue exists because their was no thought, or plan. Forget about the social or moral judgement, the fact is that the pregnancy was not considered by the woman. This doesn't apply to rape, or forced sex or in the case of medical harm to the mother. But that is a small fraction of the total cases that abortion sees today.
As some people say, the only safe sex is no sex. Countries as a whole have not thought about it, other than, oh boy more voters. But their concern should have been how can we provide for this ever increasing population? Take CA for ex with 40 million people double what it was in the 80s. Yet, they have not doubled their resources and infrastructure to handle the increase. CA is basically a desert, and they have not captured the water provided by nature. EPA doesn't apply to putting dirty runoff water directly into the ocean, or sewage overflow also into the ocean. It is like using your bathtub instead of the toilet, gross.
del if you wish.