The Problem Of Consent If I understood correctly what you meant by "consent to be brought into existence", I think that we cannot talk about giving consent in such a situation. Consent is defined as "permission for something to happen or agreement to do something". I don't think consent, as we have defined it, can be given before being born. A similar line of reasoning can be applied to the fear of death: you are dead, you cannot feel pain and you cannot experience human emotions as we know them, since your body and all the functions related to it can't coexist with what is know as "death" (of course, you can be scared of what might happen to the people around you after your death) . If you are not yet born, you cannot give consent since you don't have any of the brain function and any of the experience needed to actually give consent. And even when you are born, you still haven't developed all those functions yet. That's the reason why there is an age of consent for sex in the first place, for example. How can you give or not give consent to something you now absolutely nothing about? Now, I'm sorry if I wasn't really clear, but English isn't my first language, I'm quite young and don't have a solid philosophical education. Also, it's my first time writing on this forum so forgive me if I have made any mistakes.
P. S. I'm talking in atheist terms, so your idea of an after life and of what we were (or where we were) before being born could be different from mine.