A six-month-old baby died in the arms of their mother after she fell asleep having drunk "two or three" bottles of wine, a safeguarding report has found.
The baby, referred to as Infant 1 in the report published by Derby and Derbyshire Children's Safeguarding Board, was found by the infant's father after he returned home.
The mother was asleep with the baby's "apparently lifeless" body between her and the arm of the chair.
Attempts were made to resuscitate the baby but it died two days later.
The report states that the mother had a history of "chaotic alcohol abuse" during times of stress and had drunk and smoked during her pregnancy.
The woman, who also has another young child, had been observed by a professional drinking wine while making tea but denied drinking alcohol when questioned.
She insisted she did not have a problem with alcohol abuse after the baby's birth, saying it was only "occasional consumption".
She was prescribed medication for anxiety and low mood, having stopped taking it during her pregnancy.
At one stage she was reported missing with her two children by her sister to police because of the concerns about alcohol usage. Her husband also reported her to police for driving with the children when she appeared to him to be "obviously under the influence of alcohol".
Despite the woman being confronted by a professional about her alcohol consumption, they nevertheless believed her when she told them the problem was "under control".
The report said that there was "no clear risk assessment" carried out to investigate whether the mother's need for alcohol overcame her ability to provide safe care to her children.
After the baby died, the mother admitted to drinking wine before passing out while holding her baby. The report said the father "subsequently presented a picture of persistent, heavy drinking for many years, which was very different from that presented" by the mother.
The report criticised professionals for accepting the mother's "own script" about her drinking and that "some information which could have challenged that view was not shared fully across all agencies".
It added: "Had the information that emerged after Infant 1’s death been fully shared beforehand it could well have shaken the confidence of professionals that this baby was safe and led to more assertive safeguarding action."
The report suggested that professionals should not rely on a carer’s account of the amount and frequency of alcohol or drug use.
Infant 1 suffered "preventable harm" and had "died from oxygen deprivation to the brain as the result of unsafe sleeping with neglect a significant feature of the case", the report said.