First up, welcome and congratulations on your first child.
As to the problem I would suggest bringing it up as a question at first. When you're sitting around with your parents, and only them, initially, just bring up the subject of atheism/non-belief without specifically stating that you now fall into that category and see how they react. It will give you an idea of how they will respond to you.
In the end, it's up to you how you want to bring it up and when. I would be non confrontational about it and just talk through how you feel, how you came to your conclusion and how you want to keep your own family out of it.
If your parents are anything like my mother, they'll try to guilt trip you with the whole, "how have we failed you?" nonsense.
Stand strong. Be yourself. Be open and honest. Don't let them guilt trip you.
As to the problem I would suggest bringing it up as a question at first. When you're sitting around with your parents, and only them, initially, just bring up the subject of atheism/non-belief without specifically stating that you now fall into that category and see how they react. It will give you an idea of how they will respond to you.
In the end, it's up to you how you want to bring it up and when. I would be non confrontational about it and just talk through how you feel, how you came to your conclusion and how you want to keep your own family out of it.
If your parents are anything like my mother, they'll try to guilt trip you with the whole, "how have we failed you?" nonsense.
Stand strong. Be yourself. Be open and honest. Don't let them guilt trip you.
Playing Cluedo with my mum while I was at Uni:
"You did WHAT? With WHO? WHERE???"