An inquest has been told there was virtually no chance of saving a Waikato woman who died six hours after giving birth.
A coroner is hearing about events that led to the deaths of Casey Nathan and her newborn boy Kymani in May 2012. The baby died two days after being born.
Expert witness Mark Smith said on Wednesday that the 20-year-old woman's loss of consciousness in a birthing pool started a catastrophic decline.
Dr Smith said she was in a critical condition by the time she got to hospital and had acute kidney failure. He said multiple systems in her body failed, and there was essentially no chance of rescue.
"At the point of arrival at hospital, Casey's condition was critical in a rate of decline whereby the likelihood of rescue was close to nil. During the one hour, thirty-six minutes between Casey arriving at hospital and her death, her coagulation system rapidly worsened to uncompensated failure."
St John ambulance told the hearing that it was the midwife who remained in charge of Ms Nathan's clinical care and its staff felt excluded.
The inquest was played audio of calls between ambulance and hospital staff working to save Ms Nathan. They reveal one worker was so concerned about what was unfolding that she made a point of recording the communications.
A paramedic is heard saying that Ms Nathan's uterus had ruptured and that the midwife had no idea what was going on. The midwife said in cross-examination that she did not believe there was a rupture.
In her own evidence, the midwife said the ambulance worker was not conducive to her handing over care. Giving evidence via video link, she cried as she expressed her condolences to the mother and child's family.