Don’t necessarily assume you won’t get the job just because you have a baby (that might possibly interfere with your availability for the work)… At some point we have all said things we wish we hadn’t. But don’t give up just because of that… I have often said that the difference between a good carpenter and a bad one is that the good one knows how to fix their mistakes (my grandfather did carpentry). Instead of dwelling on possibly having revealed a fact you didn’t intent to bring up, a good idea would be to move the conversation to something more business or skill related. The truth is if hired they would eventually know you have a baby, though I get that it might not be your plan to bring that up right away. Anyway OP, don’t give up. I wish you the best.

You do know that using that as a selection choice is illegal, right? The challenge would be proving it if you don't get the job offer.

You might as well have told them about your bank robberies! If anything marks you as unemployable, it's having children. If anything could be worse, it's openly admitting you have children.

Never offer information you don't have to in an interview.