Passing sentence, judge Mr Justice Garnham said Mayo decided that Stanley “could not live” as soon as he was born.
“You assaulted him about the head,” the judge told her. “How you did this is not clear, but I suspect you crushed his head, probably beneath your foot.
“It certainly caused him serious damage, but that assault did not kill Stanley.
“He remained alive. You decided you had to finish Stanley off by stuffing cotton wool balls into his throat.
“As difficult as your circumstances may have been, killing your baby son was a truly dreadful thing to do.”
Stanley was born full-term and is said to have lived for at least two hours.
Mayo cried as she was led back to the cells.
Mayo’s defence lawyer, Bernard Richmond KC, said Mayo was a “pathetic and vulnerable individual” who was “immature” and had not been supported by those around her.
On the night she gave birth, Mayo’s father Patrick, who Mr Richmond said could be “emotionally cruel”, was having home dialysis in an upstairs room, assisted by her mother. Patrick Mayo died 10 days after Stanley was born.
Before the judge passed his sentence, Mr Richmond said: “When faced with a decision she had to make, she did not face up to it. By the time she had to, the decision she made was woefully, woefully wrong.
“This was a 15-year-old girl who was vulnerable and used by people around her and wasn’t supported.”
The judge told Mayo she was clearly “frightened and traumatised” by the birth, adding: “I have no doubt it was painful and overwhelming for you. It seems you did not cry out, so anxious were you not to disturb your parents upstairs.”
Jonas Hankin KC for the prosecution argued that the killing of baby Stanley was premeditated. “Paris Mayo clearly intended to prevent the discovery of the pregnancy or the existence of the baby,” he said.
“A decision was made to eschew help from her mother, father, or the emergency services and kill her baby.”
Worcester Crown Court heard Mayo gave birth to Stanley alone in a living room.
After delivering her baby, weighing 7lb 12oz, the prosecution said the teenager assaulted Stanley.
Mayo is said to have tried to cover up both her pregnancy and the birth – claiming she was unaware she was expecting.
She had earlier denied causing Stanley’s complex skull fractures, claiming her son had the umbilical cord around his neck, hit his head on the floor during labour, and was already dead when he was born.
When Mayo and Stanley were taken to Hereford County Hospital, the teenager was asked why she had not told her mother what had happened.
“She’s got a lot going on with dad,” she is said to have replied.