The rostering system, called Birthrate Plus, had been criticised by the NSW Nurses and Midwives Association because it does not count babies as patients.

Members of the Association want transparent nurse-to-patient ratios, and on Thursday they took to Wollongong’s Eat Street markets to publicise their campaign for change.

They said the rostering tool was easily manipulated, was treated as a “maximum” staff level, and should count babies as patients.

But Illawarra Shoalhaven Local Health District (ISLHD) executive director of nursing and midwifery Deborah Cameron said the staffing system had been agreed – with the Association – under the nurses and midwives’ award, and was used in all health districts statewide.

“It allows flexibility to allocate nursing hours in a way that matches the busiest times and patient needs,” Ms Cameron said.

Ms Cameron said the staffing tool included assessment of babies’ care needs.

“In 2011, NSW Health and the NSW Nurses and Midwifery Association committed to calculating staffing in maternity services using an evidence-based midwifery workforce planning tool that has been applied to maternity services throughout Australia, Ireland and the UK,” she said.

“The tool provides a framework to calculate the number of midwives required to meet the needs of women for midwifery care throughout pregnancy, labour and the postnatal period.

“The tool includes an assessment for the care of the baby as well as the mother.”

NSWNMA organiser Alistair Ball said the system should change because it’s possible to have “one midwife with six mothers and six babies – a total of twelve that they’re expected to care for”. 

But in 2014 the NSWNMA was praising the Birthrate Plus tool as a “union-negotiated tool” that delivered staff increases for maternity.

Asked about this, Mr Ball said the tool worked well “when applied correctly”.