Vets at Adelaide Zoo believe it would have been near impossible to save Sumatran orangutan Karta, who died last week after delivering a stillborn infant.

An autopsy has found the placenta did not detach properly, which led to internal bleeding.

“The only curative action would have been to reset her uterus, so give her a hysterectomy,” senior veterinarian Ian Smith said.

“And she wouldn’t have been a very good candidate for that, given her history and also by the time we were able to diagnose it she certainly would have been very compromised.”

Karta has had a long and heartbreaking history of childbirth, losing six infants previously.

It was on contraception when it fell pregnant this time, but the zoo decided to proceed because the species is critically endangered.

“It’s probably an unusual diagnosis, a lot of orangs in the world, you wouldn’t necessarily pick up a diagnosis if this occurred,” Dr Smith said.

“Particularly having a number of infants in the past so there’s more uterine scarring, there are not as many places for that placenta to attach safely.

Karta’s baby confirmed as stillborn

The late Karta (L) and her partner Kluet had seven failed attempts at parenthood. Photo: ABC

The autopsy also confirmed that Karta’s baby was stillborn.

“The baby we think died more because of Karta’s compromise, so the blood loss had compromised the blood supply to the baby and it was dead before it was born,” Dr Smith said.

“We’ve still got to wait on some histology [tests] to come back to look at the baby’s lungs to see whether it breathed in some of this blood loss.”

Dr Smith said the problem would have been extremely hard to pick up in an ultrasound.

“The ultrasounds we were able to do, while there were fantastic, they were only really flashes of what’s going on just to make sure this baby’s healthy,” he said.

“We couldn’t actually diagnose the fine layers in the placenta to see where it was attaching.”

Karta’s keepers in mourning

The death had a huge effect on staff, especially Karta’s two immediate keepers.

“It’s still very raw for a lot of staff and there’s some staff that haven’t been able to come into work properly yet,” Dr Smith said.

“We’re offering them professional help as well as support from the rest of the team.

The zoo’s chief executive, Elaine Bensted, said it had received an overwhelming amount of support from the public.

“We set up a special site where people could leave condolence messages and we’ve had over 2,500 people leave condolence messages,” she said.

“There have been some people coming in just so they could come to the orangutan space and watch Kluet.

-ABC