There were "significant failings" in the months leading up to the moment a woman threw herself and her baby off a cliff, a psychiatrist told an inquest.
Charlotte Bevan, who had schizophrenia, walked out of St Michael's Hospital in Bristol last December with her newborn daughter Zaani Tiana Bevan-Malbrouck.
Their bodies were found in undergrowth in the Avon Gorge days later.
Dr Laurence Mynors-Wallis said an "important contributory factor" was the "lack of multi-disciplinary care plan".
Avon Coroners Court heard the 30-year-old mother had stopped taking an anti-psychotic drug over concerns about breastfeeding.
Dr Mynors-Wallis, the former associate dean of the Royal College of Psychiatrists, told the inquest there were several warning signs in the run up to the tragedy.
He said Ms Bevan could have been sent to a different unit or been assigned a one-to-one specialist mental health nurse.
"There wasn't a waterproof care plan in place," he stated.
"A care plan is core to delivering the interventions that are needed for people with mental illnesses, especially those who are going through childbirth - which is a stressful experience.
"It is important as well because she would be coming into contact with a series of professionals who aren't experts in mental health."
The sixth day of the inquest was told Ms Bevan had a long history of mental problems, had been sectioned on four occasions and had self-harmed.
Dr Mynors-Wallis said after coming under the care of Bristol North Recovery Team there was clear evidence Ms Bevan was becoming unwell.
He also questioned whether St Michaels had been the ideal place for her to give birth.
He said nurses on the ward had not been trained to deal with "complex" patients like Ms Bevan who may have thought her behaviour was that of an exhausted mother.
The inquest continues.