The surgeon who delivered Oliver when he was born said “the old story,” referring to the fact that he was born out of wedlock like many poor babies.
Oliver’s mother (Agnes Fleming) was not married. She actually had a relationship with a wealthy gentleman named Edwin Leeford, but did not marry him. This is why she did not have a wedding ring when Oliver was born.
The surgeon leaned over the body, and raised the left hand. 'The old story,' he said, shaking his head: 'no wedding-ring, I see. Ah! Good-night!' (ch 1)
His mother is described as young, and “a good-looking girl.” She showed up very weak, had her baby, and died. As a result, Oliver was at the mercy of the workhouse. He was destined to be a poor orphan, the illegitimate son of a gentleman. Of course he did not find out any of this until much later.
Dickens pitied unwed mothers and even prostitutes. We see this in his sympathy for Agnes, Nancy, and Oliver. To Dickens, all babies were born equal and good. It was only society that marked them useless and threw them away.