Indian dentist Savita Halappanavar, who died after being refused a termination as she miscarried, could be alive if medics had not missed a series of symptoms and signs throughout her care in hospital.
A damning report into her treatment at University Hospital Galway found 13 missed opportunities to spot a significant deterioration in her health over three days fr om the time of her admission.
Medical staff failed to give her the most basic care, the Health Information and Quality Authority (Hiqa) found.
Phelim Quinn, the watchdog's director of regulation, said Ms Halappanavar could still be alive if medics had not missed a series of signals during her time in hospital.
"Each of those signs, we believe, could have been recognised as a sign of deterioration, or a sign of a developing infection or developing sepsis," he said.
"If they had been taken we believe it could potentially have changed the outcome, so yes it could mean she would be alive."
Ms Halappanavar died in the Galway hospital on October 28 last year.
She was 17 weeks pregnant when she was admitted a week earlier, having a miscarriage.
She also suffered septicaemia.
The Hiqa inquiry has found that ultimate clinical accountability rested with her consultant obstetrician, Dr Katherine Astbury.
It stated that Dr Astbury was the most senior clinical decision-maker treating Mrs Halappanavar and should have been suitably clinically experienced and competent to interpret clinical findings and act accordingly.
"Ultimate clinical accountability rested with the consultant obstetrician who was leading Savita Halappanavar's care," Hiqa stated.
It is the third inquiry into Mrs Halappanavar's death from sepsis after i nvestigations by coroner Dr Ciaran McLoughlin and the Health Service Executive (HSE).
Dr Nuala Lucas, a consultant anaesthetist and Hiqa investigator, said she endorsed the remarks of Hiqa chief Mr Quinn.
"Young women, young patients don't just die," she said.
"If they become ill, they start going on a slippery slope and you generally have several opportunities, if you can detect that deterioration, to reverse the outcome for that patient."
Dr Lucas said the "crux of the matter" was a failure to recognise that Ms Halappanavar was deteriorating and, because of that, a failure to respond in the right way.
Key findings of the Hiqa report included:
:: General lack of provision of basic, fundamental care, for example, not following up on blood tests as identified in Mrs Halappanavar's case;
:: Failure to recognise that Mrs Halappanavar was at risk of clinical deterioration;
:: Failure to act or escalate concerns to an appropriately qualified clinician when Mrs Halappanavar was showing signs of clinical deterioration.
Last April, the coroner found Mrs Halappanavar died because of medical misadventure while the HSE inquiry highlighted a number of failures by medics looking after her.
Praveen Halappanavar, Savita's widower, is taking legal action against University Hospital Galway over alleged breaches of medical practice.
Hiqa issued a damning verdict on the medical staff at the hospital.
It said the consultant, non-consultant hospital doctors and midwifery and nursing staff were responsible and accountable for ensuring Mrs Halappanavar got the right care at the right time but they did not.
Hiqa criticised the record keeping at the hospital and the management of patients attending obstetrics clinics.
In Mrs Halappanavar's case, it found evidence of a number of retrospective entries into her notes two weeks after her death - an issue which had been raised at an inquest.
Other findings from Hiqa include:
:: Vital hospital policies were not in use nor were arrangements to ensure basic patient care on St Monica's Ward, such as observation of obstetric patients;
:: Early warning score charts were not used in the ward;
:: There was no formal clinical escalation protocol and no emergency response team at University Hospital Galway;
:: Consultant obstetricians on-call in the hospital's labour ward were not present in the ward but off doing other duties - against the best national and international evidence.
Hiqa said there was a "disturbing resemblance" between Mrs Halappanavar's death and the case of Garda Sergeant Tania McCabe, who died in 2007, along with one of her newborn sons shortly after giving birth to twins.
Hiqa has called on the Galway Roscommon Hospital Group to consider the actions, omissions and practices of the nurses and doctors who treated Mrs Halappanavar and refer them to professional regulatory bodies if necessary.
The HSE has been ordered to review staff numbers for national maternity services to ensure teams have sufficient staff with the right mix of skills and deployed effectively in daytime and for on-call hours.
Separately, the HSE and Department of Health have been told to prioritise a review of national maternity services and put together an agreed standard of care and support for pregnant women on a 24-hour basis.
Ireland has boasted one of the lowest maternal death rates in the world with the figure down to eight per 100,000 births in 2009 and 2010.
But Hiqa said it had found that maternity services may not be as safe as they should be or of sufficient quality and that needed to be urgently addressed.