The public health watchdog says a midwife failed to recognise that a difficult birth was quite different from what would be normal.
Health and Disability Commissioner Anthony Hill says a self-employed community midwife, hospital midwives, an obstetric registrar and the Waikato District Health Board all breached patient rights over the birth in 2009.
Linda Barlow had had a difficult first birth and wanted her second one to take place in hospital, rather than at home or at a birthing clinic.
The Hamilton woman was persuaded by her midwife Jennifer Rowan, now Jennifer Campbell, that this wasn't necessary, but the birth went badly. The boy, Adam, was eventually born after an emergency caesarian, but died shortly afterwards.
A coroner said failures by Ms Campbell contributed to the death and that has been supported on Wednesday by the commissioner, who has referred the midwife for possible further legal action.
Ms Campbell is being criticised for severe and repetitive failures in the care she gave Mrs Barlow. Mr Hill said she made errors, including sending the mother home from the birthing clinic while in labour, in pain and worried.
"The heart of what failed here was that failure to recognise that what was occurring was starting to differ significantly from what would normally be expected. That failure to recognise that deviation meant that there wasn't early enough referral and help wasn't obtained as it ought to have been," he said.
Linda Barlow told Radio New Zealand's Checkpoint programme on Wednesday that Jennifer Campbell was self-employed, in her first year of practice and under a midwifery programme.
"Even though she was under that programme it still failed to support her and it didn't work in this case, because I just still feel that a new graduate midwife should not be able to practise self-employed and independently in the community."
The Waikato District Health Board says improvements have been made to prevent confusion arising in certain emergency situations.
The commissioner says the community midwife failed among other things to clarify who was responsible for Mrs Barlow's care at the hospital.
The DHB's chief operating officer, Jan Adams, told Checkpoint that kind of confusion shouldn't happen again.
Ms Adams says the board has a tool used for communication across the organisation - and specifically in midwifery - so there is a very careful process for ascertaining all of the information around a woman.