It is ALWAYS good policy to save a child. If the prognosis is good, as it is more and more as science progresses, it is most definitely good policy. I'm personally stunned by the implications of your post, frankly, whether they are intended or not.
Why are such massive interventions not resisting the will of God? Because He gave us the intelligence and means to make medical advancements, and common sense to know when to draw the line. He gave the Israelites basic instruction on how to stay healthy and live long lives. It certainly sounds like He sanctions the field of medicine to me. One of the gospels was written by a physician. You read His words and tell me that He doesn't think it is good policy to save a child whenever possible and I'll stand corrected.
Which seems to have gone dormant, doubtless due to lack of exercise, in a great number of people.