In a previous post I wrote about us humans being relatively badly designed for childbirth compared to the other great apes. (Post #3 http://pregnancyandchildbirtharoundtheworld.blogspot.com/2011/10/childbirth-are-our-bodies-designed-for.html). Because of our large brain size our babies have big heads, and because we walk upright our pelvis has a small hole – the combination of these two factors can be lethal for mother and baby.
When you think about it, this is a pretty major design fault. No doubt some population geneticist could explain the costs and benefits to me, but from a species point of view (never mind the individual woman’s point of view) it seems odd to kill off one generation in producing the next.