Auckland District Health Board spokesman Matthew Rogers said the board was unable to comment without consent from the patient's family but they were feeling for those involved.
On Wednesday, Gayo said he could not understand why his wife died.
"It's shocking, my wife was very healthy. We were so happy because we were going to have a baby."
She had had her labour induced 10 days after her due date, but her pregnancy had been trouble-free.
Leah's midwife was away when the couple arrived at the hospital at 11am on April 20, so another midwife took over her care - she in turn was relieved by another later in the day. "She'd delivered three babies that day."
Labour continued until Leah told him to get the midwife about 1am.
"My wife was in very much pain. The midwife saw the monitor and she called the doctor. The doctor said we need to let the baby come out."
Before that could be done, Leah suffered a stroke and subsequent tests showed she was brain dead.
An autopsy report listed the cause of death as "complications of childbirth, pending further investigations" and the death has been referred to the coroner.
It is the same autopsy finding as the death of another mother, Casey Nathan, who died along with her newborn son during birth a year ago in the Waikato.
Leandro remains in hospital, but is expected to be discharged this week into the care of a foster family until Gayo returns.
Leah was a former teacher but the couple had both worked as bakers since they moved to New Zealand five years ago, wanting a better life for their children.
Members of the New Zealand Filipino community, the couple's church and their workplaces had fundraised to help Gayo pay for the funeral and airfares for himself and the couple's daughter, Kyla, 10, but he was still $3,000 short.
Donations can be made to Westpac account: 03 0155 0684611 025 Tabang Gayo/KBNZ.