"She said that, although she was uncertain, she was embarrassed to ask for help," the commissioner found.
He said that if the midwife remained uncertain, she had a professional obligation to act on her concerns.
The woman's LMC and a senior hospital midwife also failed to appropriately monitor the maternal and foetal wellbeing. The LMC left the hospital without adequately arranging for an epidural or handing over the woman's care to hospital staff.
The clinical midwife manager provided inadequate supervision to the hospital midwife.
The commissioner said the DHB's system, designed to ensure that patients receive timely, appropriate, specialised care, failed to deliver. Several providers and the DHB's systems let the woman down and breached the Code of Health and Disability Services Consumers' Rights (the Code).
The HDC made a number of recommendations that have been complied with.
Ms B, Ms C and Ms D all wrote letters of apology to Ms A for their breaches of the Code.
NDHB carried out an internal review after the incident and made significant changes to its systems, including training on the use of CTGs, and added supervision and education for new midwives.
Mike Roberts, NDHB chief medical officer, said guidelines had been put in place to ensure that care is delivered in a consistently safe manner.
"We have increased staffing levels significantly and have recently been recognised as leading the way with the implementation of the new National Maternity Quality and Safety Standards," Dr Roberts said.