You do realize, don't you, that your standard includes children that have been around for a while? Think of it this way.
Take an unborn child out of the womb, lay it next to a newborn child, and next to that a child aged 4 months. Walk away and come back in a week.
Which of the children will be alive?
IOW, "viability" is not a good standard unless it is defined, and when it is defined, includes either the unborn or the already born in ways not intended.
viability when talking about pregnancy is defined by whether a fetus can sustain life outside the mother womb. Thus- children who have already been born are already excluded from the conversation.
fetus' before viability do not have the ability to keep themselves alive because they are NOT fully developed. They are developing.
fetus' after viability have developed enough of their body to live. They have brains, they have lungs, they have kidneys, they have a shot at life outside the womb. They are no longer a cluster of developing cells but they are now
developed. They are a baby, a person, a child. Compared to the unviable fetus.
That is my opinion, and the opinion of our law.