I think there are a lot of harsh “blanket” replies above, when it absolutely completely depends on the person, their condition and how they manage it, what other support you have etc etc.
I would say wait til he is in a stable place and is managing his condition well. Have coping strategies in place, try to prepare as much as possible for the realities of having a child and how they’re likely to affect him and you.
I have had a child with someone with anxiety and depression. He was in a good place when we had our baby but the stresses and strains of caring for a small baby (and moving house! Not our best planning!!) put him into a bad place. He had a very scarily bad episode but has managed it well. Yes it is exhausting when he is struggling with his MH but I don’t for a second regret having our DD together.
He is a great dad and she adores him, she’s very stable, happy, lovely. I don’t think you’re any more selfish than any other parent! It just needs some serious planning and putting safety nets in place (eg support for you too).
I would also say maybe make it clear that you will remove yourself and child from the situation if he is not managing his condition and / or refusing to accept he needs help at any given time. Make sure he takes full responsibility for himself and his mental well-being and that he knows your number one priority will be the child.
Good luck with whatever you decide to do.
As another PP said, we all have Mental health. What counts is how you maintain / troubleshoot it!