The lead maternity carer of a woman who died after giving birth and of her son who died two days later told an inquest a family member threatened her saying: "You are going to pay for this, I'll hunt you down.''

The woman, whose identity and whereabouts have been suppressed by coroner Garry Evans, appeared via videolink this morning at the inquest into the 2012 deaths of Casey Nathan and her newborn son Kymani.

She began sobbing when she described the moment when Casey Nathan fainted while she was in a birthing pool as her labour started to prolong.

"Up until this time all observations of Casey and baby appeared to be normal,'' she said.


The woman said while the baby's head was coming out it was difficult to trace his pulse.

When he was born he was "pale and limp''.

She told the inquest that following the delivery of Kymani, who was rushed off to Waikato Hospital, she tried to push the trolley Ms Nathan was on to an awaiting ambulance.

"I went past Casey's family in the hallway and one member threatened me saying: "You are going to pay for this, I'll hunt you down.''

She said while she tried to check on Ms Nathan while in the ambulance she was told to "f### off b##ch''.

The inquest, in Hamilton, is set down until at least next Monday.