I'll agree that the decision to do either is selfish. I have my own selfish reasons for wanting children, just like you have your own for not. However...procreation is part of the definition of life itself. I don't think birds are selfish for having little baby birds or flowers are selfish for spreading their pollen
Edited to note that the word "selfish" looks very strange when you type it several times in a row, and that I misread what Valkyrie was saying so I'm removing her quote from my post!