About 13 yrs. My ex gave up a baby for adoption. My name is on the birth certificate, however, is there any way of finding out if the child was mine or not? I was young at the time and didn't think this would ever come back to haunt me, but I'm finding that it is.

If your name had been on the birth certificate, you would have had to sign away your parental rights.

Barring that, it would be very disruptive to the child for you to try to find out NOW what you should have been more interested in years ago.

I would leave well enough alone.

If your name was on the birth certificate you would have been a part of the adoption process. If you signed away your rights, the child is not yours anymore, so what biology will tell you is irrelevant.