A woman who killed her baby son when she knocked a television on his head while high on drink and drugs has been jailed for 15 months.
Natalie McMillan, 25, put her "self-indulgent drugs lifestyle" ahead of the welfare of her son Kian, who died from "catastrophic injuries", Preston Recorder Judge Anthony Russell QC said.
The baby boy was lying on his changing mat at the family home in Burnley, Lancashire, when his mother attempted to move the TV to plug in a scart lead and watch a DVD.
While giving evidence at her trial at Preston Crown Court, she tried to blame Kian's father - her ex-partner Edward Hanratty, 41 - and said she was upstairs in bed at the time.
McMillan denied she had been under the influence of drugs when her son died, but tests later showed she had taken heroin and valium.
Hanratty had also taken drink and drugs, and had passed out on the kitchen floor at their address on December 6, 2011.
Both pleaded guilty to child cruelty on the basis of neglect during their trial last month.
McMillan was cleared of manslaughter by gross negligence, but Judge Russell said he was satisfied it was she who actually moved the television through "foolishness".
Hanratty failed to attend for his sentencing and a warrant for his arrest has been issued.
Sentencing McMillan, the judge said: "Over the short life of your child it is apparent that both you and your partner gave priority to your selfish and self-indulgent drugs lifestyle and neglected the welfare of Kian.
"On the night he died, both of you were so intoxicated by drugs and alcohol that you probably forgot all about him with the tragic consequence that he died."
He added that it was clear McMillan had been concealing the extent of her drug addiction from social services and health teams for a long time.
She had also hidden her relationship with Hanratty, who was known to social services for previous welfare issues with other children.
Peter Wright QC, defending, said McMillan had made "considerable improvement" since descending to the "depths of the spiral of drink and drugs".
He added: "This is a young woman who is emotionally detached. This emotional detachment may be long term by reason of her own life by what occurred in infancy and subsequently in adolescence."
Detective Inspector Mark Rothwell from Lancashire Police said: "This is a tragic case in which a four-month-old baby has lost his life in the most tragic of circumstances.
"Natalie McMillan was in no fit state to look after Kian that night, and this should serve as a warning to people and highlight the most serious of consequences of caring for children, especially young babies, whilst under the influence of drink and drugs.
"From the moment Natalie McMillan dialled 999, to her sentencing, she has shown absolutely no remorse and will now have a period in custody to reflect on her actions and the impact that drugs have had on her life."