Medical staff leave one equipment wey big like "dinner plate" inside one woman belle for New Zealand afta she born through Caesarean for one Auckland hospital.

Di equipment, Alexis wound retractor - na soft instrument wey be like tube, wey dem dey use hold open surgery wounds - bin dey inside her belle 18 months afta she deliver before dem remove am.

Inside dat 18 months, di woman suffer pain no be small and she go hospital tire before dem find am for one CT scan.

Health regulators say di public hospital system fail di patient.

Initially, district health authorities Te Whatu Ora Auckland bin dey argue say na lie, say dem no fail to give di woman beta care.

But New Zealand Health and Disability Commissioner disagree for result of investigate wey dem release on Monday.

"Evidence show im sef say di care wey dem provide fall below di proper standard, becos dem no identify di [retractor] during any routine surgical checks, dat na why dem leave am inside di woman belle," Morag McDowell say.

"Staff wey dey involve no get any explanation of how di retractor end up inside di belle, or why dem bin no notice am before dem close her," she tok.

Di Alexis wound retractor na big object wey dem make from transparent plastic wey dem fix on two rings. Dem dey remove am afta dem close di uterine incision for C-section operation and before dem sew di skin up.

Becos na "non radio" item wey no dey transparent, x-ray scan bin no fit see am.

Di team for Auckland City Hospital wey bin attend to di woman bin replace di first Alexis wound retractor wey dem bin use for bigger one. Na dis second one na im dem leave inside di abdomen.

Di Commissioner say dis na di second time inside two years wey dem dey leave surgery equipment inside patient for Auckland hospital.

Di hospital suppose get beta protocol, Ms McDowell say.

"Di woman bin experience plenty pain for long time afta her operation until dem remove di [retractor] for 2021. I accept her concern about how dis affect her health and wellbeing and dat of her family," she tok.

Dem no mention di woman name to protect her privacy.

One nurse for di hospital tell investigators say dis fit be becos half of di retractor, wen dem dey use am, dey remain outside di patient and "so e no go dey at risk of being retained". E no clear how for dis case, di di whole equipment end up insde di woman body.

Al di pipo wey dey inside theatre during di woman operation include one surgeon, one senior registrar, four nurses, two anaesthetists, two anaesthetic technicians, and one theatre midwife.

Te Whatu Ora Group director of operations for Auckland Mike Shepard apologise give di patient.

"We wan assure di public say dis kain incident dey extremely rare, and we remain confident in di quality of our surgical and maternity care," he tok.

E no clear wetin di woman condition be from di commission report but notin for di report show say di woman dey harmed.

Lawyers dey review her case now to see if dem go fit carry out more action like disciplinary charges.