Two stillborn babies had their heart beats misread by midwives, the Health and Disability Commissioner has found.
In both incidents in 2007, the babies' mothers were overdue and their midwives decided to admit them to hospital to induce the births.
Commissioner Ron Paterson found that while monitoring the unborn babies' heartbeats, the midwives failed to pick up signs of distress.
The midwife of one woman admitted her error and felt responsible for the baby's death.
The report found she had failed to comply with professional standards by not carrying out a continuous heart trace of the baby before giving her patient an epidural.
She also failed to interpret the mother's heart reading correctly which led to her failure to adequately liaise with the hospital's obstetrics unit over possible complications.
She had 40 years' experience in midwifery but stopped practising after the baby's death.
"I felt responsible and accountable for my actions, which I believe contributed to this tragedy...
"I am devastated that I observed the...monitor through the day and failed to identify the seriousness of the readings."
The mother of the second baby had been sent home from hospital, before returning the next day and delivering her baby stillborn.
Mr Paterson found the woman's primary midwife had mishandled communication with the family and hospital staff, and there was confusion over whether she was clinically responsible while the woman was in hospital.
The family had asked that she only be present in a supporting role after losing confidence in her ability to handle the delivery when she lacked composure and became emotional.
A second midwife had neglected to check the foetal heartbeat and foetal movement.
The midwives concerned had been referred to the New Zealand College of Midwives for possible disciplinary action.
The Ministry of Health had a new maternity care strategy which addressed some of the issues in the cases of the stillborn babies.
The strategy included improving communication between midwives, medical practitioners and families and hospital referral guidelines.
Mr Paterson said in his report the ministry review was "a step in the right direction".
"Women in New Zealand believe that a safety net is in place if they choose to deliver their baby in a public hospital."