Follow up -- Clarifying the Hypothetical

Thanks, Michael, for your thoughtful response.  Before I go rake leaves (ugh), let me refine the hypothetical a bit, to try to focus in on the issue more carefully.  First, assume that you have no prior connection to any of the four.  You are just a firefighter, and you know from the owners of the house that there are two blastocysts in one room and two infants in another, but none of them are related (or even known) to you.  This removes the element of differential emotional attachment.  Also assume the infants and blastocysts are as healthy as they can be.  I assume none of this would change the answer you give.  Whether you feel guilt afterwards doesn't really answer the question whether this is a form of discrimination among life stages.  That is, if there were two infants in each room, you might choose the room to the left, or you might choose the room to the right.  You would still feel guilt, but you would acknowledge that you had no choice and that the choice between the two rooms had been entirely arbitrary and random.  The situation would be precisely like the one confronted by Buridan's Ass.  Maybe you chose the room on the right becuase you are right-handed or because of the color of the door or because you flipped a coin, but you would attach no significance to the content of the choice:  you just have to act.  And, without more facts in the hypothetical, there would be no claim that you had discriminated against the children you didn't pick and, really, no basis for discriminating.  (Again, the absence of discrimiantion would not reduce your feeling of guilt and sadness at being forced to make the choice.)  Is there any chance, however, that anyone would save the petri dish over the infants or go through the same random process in determining which room to enter?  I doubt it, though I'd love to hear what others on the site think.  It seems to me that the force of the hypothetical is that it taps into the intuition that everyone would always save the infants.  Does that choice demonstrate that it is rational not to treat all life stages equally?