George Brudenell was lying in the crook of mother Charlotte Hayter’s arm when she fell asleep and was in the same position, but unresponsive, when she woke.
Attempts were made to resuscitate him by his father, Lewis Brudenell, before paramedics arrived, but he died.
The William Harvey Hospital in Ashford
Recording a natural causes verdict, coroner Rachel Redman said: “George was in bed with his mother and sister. He died in his mother’s arms.
“There are dangers in co-sleeping. It is understandable that parents want to do it.”
The inquest heard that George lived with his parents in Elm Place, Ashford.
He and his twin sister, Emily, were born on December 17, last year, and he died on January 25 in the William Harvey Hospital.
Miss Hayter said that when the twins were two weeks old, they were admitted to the William Harvey Hospital with flu and bronchitis.
They were in hospital for nine days, but she said George recovered quicker than Emily. After they were discharged, George was fine and thriving.
Folkestone magistrate's court, where the inquest was heard
In a statement, Miss Hayter said the twins went to bed with her on January 24, while Mr Brudenell slept downstairs. She fed them, and they went to sleep, with George in the crook of her arm.
“We all went to sleep,” she said. “About five o’clock, I woke up and George was unresponsive. He had not moved and was how I had left him. Lewis began CPR and paramedics took him to hospital.”
“There are dangers in co-sleeping. It is understandable that parents want to do it” - coroner Rachel Redman
Paediatric pathologist Dr Liina Kiho carried out a post mortem and said George was small for his age.
Samples taken from his blood, lungs and spleen revealed evidence of the staphyloloccus aureus bacteria which usually caused infection, but there was no evidence of this in his tissue.
Dr Kiho said: “I cannot rule out septic shock due to toxins from the bacteria. It is a significant finding.”
She said she could not identify what had caused George’s death, but risk factors were that he was a twin, small for his age and was co-sleeping.
Dr Kiho gave the cause of death at the inquest held at Folkestone Magistrates’ Court as sudden unexplained death in infancy.