If you attempted to have an abortion but (the procedure) failed, would you ever talk about it with your son/daughter that you didn't want?
Yes. I would. The truth is the truth. The convo could start like this: "son/daughter, I would like to tell you about the worst decision I ever made in my life and how thankful I am for the outcome..." As long as it's presented thoughtfully, most...
... would be glad to hear the blunt honesty. If the child suffered physical consequences, this would also be the time to apologize profusely for that decision. Own up to it. Don't run from it.
What a horrible question / situation.
I would never want to kill my child.
Hey son, let me tell you about that time I almost paid to have you killed...
"I wanted to kill you sweetie, but it didn't work. Sorry about all the health problems like scorched lungs that you have to deal with because I was a selfish douche bag."
that needs to be something you just live with