An Edinburgh woman who put methadone on a baby's dummy to stop him crying has been jailed for three years.
Susan Taylor, 29, admitted a charge of culpably and recklessly causing the child to ingest methadone, to the danger of his life in November 2008.
Although Taylor admitted the charge last September, the case could not be reported until Tuesday because her partner was facing trial.
Lynn Cowan, 28, admitted she failed to tell medics the baby had methadone.
At Edinburgh Sheriff Court on Tuesday Cowan appeared from custody and halted a planned trial by admitting that when Taylor told her she had given the little boy methadone, Cowan failed to pass on the information to doctors.
A court heard that the 10-week-old child, who cannot be identified for legal reasons, almost died.
Doctors found "a huge quantity" of the drug, given to addicts to wean them off heroin, in the baby's urine.
They said it was too early to tell whether there might be lasting effects, advocate depute Morag Jack, prosecuting, told the High Court in Edinburgh.
Sheriff Alistair Noble jailed Cowan for a total of 10 months, eight months for a charge brought under the Children and Young Persons Act and two months for missing a previous court date.
The High Court hearing last September was told that the couple, who both have drug problems, regularly looked after the little boy at his home in the Leith area of Edinburgh.
Ms Jack described how they were watching television there when Cowan suddenly realised the baby wasn't breathing.
"His lips were blue and his face was grey", said Ms Jack.
By the time ambulance personnel arrived on the scene the baby was not breathing, apart from a single gasp for air.
The child suffered fits on the way to the city's Royal Hospital for Sick Children and was kept in intensive care, gradually improving over the next 36 hours.
Police were called in when tests revealed methadone was in the baby's system two days later.
When questioned, Taylor admitted rolling the child's dummy around the measuring cup she used to take her daily methadone.
The judge was also told that poisons expert Professor Robin Braithwaite had prepared a report on the case.
He said methadone presented a high risk to children because it tasted sweet. As little as half a teaspoonful could prove fatal.
Ms Jack said: "Professor Braithwaite is of the opinion that without prompt medical intervention the baby would have died"
Defence advocate Susan Duff said Taylor was "distressed" when the baby cried and she was unable to settle him.
The lawyer added: "She in no way intended to cause him any harm
"She loves him. She had no concept of how dangerous feeding methadone to a young baby was."
But Lord Bannatyne told Taylor, formerly from Leith, that she had shown "a high degree of recklessness".
Lord Bannatyne ordered the three year sentence to follow a 26-month sentence Taylor was currently serving for snatching a 66-year-old woman's bag at knife-point.