Daisy,
In all three of the cases of the babies they were born so premature that internal organs had not fully formed, they couldn't receive opiates because at their body weight, and given problems associated with respiration and heart, they would have died from the opiates.
However, in all honesty, I find your questions irrelevant. The fact is, despite being in pain for the first few weeks of their life, despite medical doctors declaring them "hopeless," they all had fulfilling lives, the pain ended, they are not massively handicapped invidiuals today.
The doctors were wrong, and had someone decided to "be merciful" and murder my spouse the two children I have would never have been born.
Doctors will ALWAYS make errors.
There will ALWAYS be miracle cures - IF - we don't take things into our own hands and decide it is "more merciful" to kill them.
Since the dawn of time men have thought they knew what was "best" and "who could survive" and they have been wrong! Babies who are born without limbs were, in some socities, considered "better off dead." We know that handicapped individuals can have fulfililng lives. Mentally handicapped individuals were considered "a burden," and "unable to enjoy life," and "not worth keeping." But a lot of people found out they are loving, viable members of society.
I have no problems with "comfort," but I have TREMENDOUS problems with, "killing in the name of comfort."