Health professionals found it difficult to identify risks with a mentally ill mother who later jumped off a cliff with her newborn daughter as she was "articulate" and "middle class", a review has found.
Charlotte Bevan, 30, vanished from St Michael's Hospital in Bristol with four-day-old Zaani Tiana Bevan Malbrouck on December 2 in 2014.
Ms Bevan, who had stopped taking anti-psychotic medication to breastfeed, carried Zaani outside in a blanket at 8.36pm, when temperatures were 3C (37.4F).
Search teams later located the bodies of Ms Bevan and Zaani, who both suffered fatal injuries consistent with a fall, on the Avon Gorge.
Avon coroner Maria Voisin later found a "chain of failures" in Ms Bevan's care contributed to the two deaths.
A serious case review published by Bristol Safeguarding Children Board (BSCB), concluded that there were eight findings in relation to the case.
One finding was that professionals may have been intimidated by Ms Bevan, described as "unpredictable and hostile".
"When confronted with this unpredictability or hostility, many professionals 'backed off' from the confrontation, leaving the issue for another time or another professional to handle without a clear documented plan of how to address these issues," the report states.
"This was compounded by what case group members described as Charlotte Bevan's intelligence and assertiveness.
"One professional described Charlotte Bevan as 'middle class', 'articulate'. This made it more difficult for professionals to identify the potential risk.
"When challenged by professionals, Charlotte Bevan was able to counter their suggestions with cogent arguments."
On one occasion, Ms Bevan refused support from a children's centre - arguing that she had lots of friends with young babies.
She initially wished to have a home water birth, which was impractical as she lived in a crowded third floor flat.
However, the midwife did not persistently challenge this as she believed Ms Bevan may change her mind.
"In fact, Charlotte Bevan's mental health and the consequent risks to the unborn child should have been the priority," the report added.
"This fundamental issue was not prioritised by professionals to be consistently tackled together."
Sally Lewis, independent chair of BSCB, said there was not "one act or omission" that would have realistically prevented the deaths.
"If all the recommendations were in place we believe that would have made it preventable," she added.
Ms Lewis said professionals were "inappropriately focused" on the needs of Ms Bevan and not baby Zaani.
"Some of the frameworks and structures around adults are more geared towards personal choice," she said.
"Within environments where a child might be at risk from a decision or an action, we would be prepared to be more interventionist for the child's protection."
The report found opportunities were missed for professionals to be supported to identify and tackle child protection issues.
A referral was made to children's social care after Ms Bevan admitted she was not taking risperidone.
However, midwives at St Michael's Hospital were not aware that Ms Bevan and Zaani were an open case and so did not notify social services of the birth.
Professionals agreed that their discharge from hospital would be delayed until a safe plan was in place for the mother and baby.
"This did not take account of Charlotte Bevan requesting early or self-discharge," the report states.
"No contingency plan was ever created for the care and support of Charlotte Bevan and Zaani Bevan Malbrouck."
Zaani, who was two weeks overdue, was born at 6.16pm on November 28, weighing 3.34kg.
Her father, Pascal Malbrouck and grandmother Rachel Fortune described her as "beautiful" and "perfect", with Ms Bevan breastfeeding successfully.
Ms Bevan's mental state deteriorated by December 1 and she left the hospital with Zaani the following day.
Carolyn Mills, chief nurse at University Hospitals Bristol NHS Foundation Trust, said: "We have a system now where you have to be buzzed out of the ward.
"Previously, there was a button you - staff, patients and visitors - pressed to exit."
Ms Fortune and Ms Bevan's sister Janet urged those with mental health problems to seek advice and support.
"As you can quite clearly see from the report, no single thing, action or person was to blame," Ms Fortune said.
"This was a particularly difficult case to manage as long-term ill mental health and pregnancy came together.
"It's our hope now that any families and individuals facing such difficulties will now have a multi-agency team with accountable clinicians in each service, as they now do in Bristol."
The family hope research, education in schools and increased awareness of mental health issues will go "some way" to prevent similar tragedies, she added.
Ms Lewis said: "A great deal has already changed in local professional practice since this tragic incident, some of which has been influenced by the findings of this review and has been noted by the board in our formal response."
Earlier this year, a new specialist community perinatal mental health service was launched for Bristol, north Somerset and south Gloucestershire.
This service is part of £40 million of funding nationally to set up specialist community mental health services for new and expectant mothers.
Dr Rebecca Eastley, medical director at Avon and Wiltshire Mental Health Partnership NHS Trust, said: "Since the deeply distressing deaths of Charlotte and Zaani, we have done an enormous amount of work to improve the care of women and their babies both during and after pregnancy."
Changes have also been made at University Hospitals Bristol NHS Foundation Trust to improve support given to pregnant women regarding mental illness.
A mental health nurse has been employed to work with obstetricians in the maternity clinic and maternity staff have been given better access to patients' mental health records.
The role of a midwife with specialist knowledge in mental health has also been developed.
Ms Mills said: "We gave a commitment to Charlotte and Zaani's family that their deaths would not be in vain and we have worked with our NHS partners to increase the support that is available to pregnant women with mental health needs."