What I personally find of value is human-like mind. It doesn't matter what it's implemented in: silicon, cells, whatever. A human child has a mind that's too primitive to be of any value, and that's only when the brain is developed. So its death seems to me to be an insignificant loss (aside from personal loss for the parents, etc..., of course).
If I have a choice to save a fully grown human (let's say 30 years old, the issue becomes more moot the older the person gets) or a child (yes, even a born child), I would sooner save the adult. A dead child is a waste of 9 months to 2 or 3 years of resources. A dead adult is a waste of many more years of resources. An adult is at the pick of their productivity, the child is not and won't be for many years to come.
If I have a choice to save a fully grown human (let's say 30 years old, the issue becomes more moot the older the person gets) or a child (yes, even a born child), I would sooner save the adult. A dead child is a waste of 9 months to 2 or 3 years of resources. A dead adult is a waste of many more years of resources. An adult is at the pick of their productivity, the child is not and won't be for many years to come.
While I agree with your first paragraph--the human mind is what matters--it might still make sense to save the child. In today's world where ...
A few years ago, I wrote a little dialogue I imagined between 2 materialists, one of whom was for and one against abortion, centering on the personal identity question. I recently cleaned it up and added a number of references for the biological claims.
You can read it at An Abortion Dialogue.
Early feedback from #lesswrong is that it's a 'nicely enjoyable read' and 'quite good'. I hope everyone likes it, even if it doesn't exactly break new philosophical ground.