If you're pro-life, how far do you take that?

[RoadRunner79]

I think that there is a lot of scenarios one could come up with, where  one may save a single person over many.   I don't  think that it is useful, if one is trying to use it as a reason to dehumanize the ones that are not saved; or to justify being allowed to kill them.  

A similar question might be, if the choice was between another person and a pregnant lady who would you save and why?

That's a fair one. If it's between a child and a pregnant adult, since many naturally seem to value children over adults. Which would you choose? What if it's one 90 year old lady or 1000 fetuses?

Would you really choose one child over 1000 adults? That seems crazy to me. Why are 1000 adults with less than one child?

The point isn't too dehumanize them, the point is that those who claim fetuses are people with rights the same as born people, don't in reality really see them as such. They are attempting to argue a point they themselves don't even truly believe.

Similar to the trolley dilemma there is the issue between saving, and actively killing.  Or the similar argument, if one should be forced to give up a kidney to save another.

I would be uncomfortable in assigning worth as a human being, to any that you chose not to save.  If you choose a child over an older person (to save), I don't think that the older person is less human, or able to be discarded.  Similarly I might choose someone to save, who makes great contributions to society, over one who is little more than a leech on others resources;  but, it wouldn't follow that I would condone the euthanasia of the person who is a drain on his community.

I don't think that everyone is equal (in many ways).  Yet they are equal as human beings. And  I'm leery of assigning value as human beings, the way you seem to be seeking here.  In all these scenarios, there is a choice.  And one where many people are going to pick one side based on a number of different reasons (logical or personal).  I think that it's kind of scary when you start making this into a math problem, and start talking about value.  I also don't think that ethics is just based on logic, science, or doing the math either.  And sometimes I think that's the point of mental exercises such as the trolley problem.  It's not in getting the correct answer, as much as if we don't struggle with the dilemma.