The Wollongong baby bungle – reported as an “expressed breast-milk error” – happened in 2013, Illawarra Shoalhaven Local Health District director of clinical operations Carolyn Cooper confirmed on Friday.

“The error was discovered within minutes of the incident occurring and staff involved completed all necessary actions for the management of neonatal exposure to breast milk from a non-birth mother,” Ms Cooper said.

“This included advising both families of the incident under open disclosure.” 

The Wollongong mix-up was one of seven incidents at public hospitals across the state between 2011 and 2015, details of which surfaced this week. Other incidents occurred at Campbelltown, Grafton, Tweed, John Hunter, Westmead and Gosford hospitals.

In a statement, a NSW Health spokeswoman said in all cases the error was discovered promptly after the incidents occurred. 

“As soon as staff realised a baby had been given to the wrong mother to feed, the families were advised,” the spokeswoman said. “NSW Health applies strict protocol for identification of newborns to avoid the possibility of babies being lost, misplaced or switched while in hospital.”

NSW health minister Jillian Skinner said babies being handed to the wrong mothers was “an extremely rare occurrence”.

“Hundreds of thousands of babies were born in NSW public hospitals over the past five years and there were seven occasions where this error occurred,” Mrs Skinner said.

The minister and Ms Cooper reiterated the strict protocols in place were “regularly reinforced with midwifery staff”.

“In the rare cases where an error occurs, immediate serological tests and breast milk screening are undertaken. The affected mothers are offered counselling and support,” Mrs Skinner said.

The NSW Health spokeswoman said newborns have identification bands placed on each ankle “as soon as is practical after birth and before leaving the birthing room or operating theatre”.

“Maternity services in NSW public hospitals do not separate mothers and babies either in the birthing unit or on the maternity ward unless there is a medical reason that necessitates the baby being transferred to higher level care,” she said.