Based on the doctor's opinion, would the son have lived if he had not been born in the eighth month, or would his demise have come to him anyway?

Patience in the face of losing a child brings immense reward. Allah Almighty has promised Paradise to the believer whose beloved is taken in this world and who endures with forbearance. It has been reported that Allah builds a house in Paradise called "Bayt al-Hamd" (the House of Praise) for whoever praises Allah and says "to Allah we belong and to Him we shall return" upon the death of their child. As for the question about knowing what would have been if something had not been, this is known only to Allah alone. Ibn Taymiyyah indicated that to assert definitively whether a slain person would have died or not died if they had not been killed is ignorance, because divine decree preceded their death by that specific cause. Therefore, it is advised to turn away from such questions as they may open doors to despair and discontent with what is predestined.