According to the Illawarra Shoalhaven Local Health District (ISLHD) whooping cough in NSW has been increasing since mid-2014; with 177 reported cases in January 2014, increasing to 501 in December 2014 - mainly across the 0-14 year age group.

ISLHD director of Public Health Curtis Gregory said epidemics occurred every three to four years, as community immunity wore down.

"The last outbreak was in early 2012 and we are seeing the kinds of numbers that indicate we are experiencing another one," said Mr Gregory.

"We urge pregnant women to ensure they are vaccinated in their third trimester, ideally at 28-32 weeks, as it offers the best protection for babies until their first vaccination.

"It is vital that parents also ensure all their children are up to date with their vaccinations to minimise the risk of whooping cough circulating in the family."

This comes amid Prime Minister Tony Abbott's announcement of the "no jab, no pay" policy last week, whereby parents who chose not to immunise their children could lose childcare and family tax payments, worth up to $15,000 a child.

The move was backed by national reports that 39,000 Australian children under seven were not vaccinated because their parents were vaccine objectors.

Figures in the National Health Performance Authority showed the Illawarra-Shoalhaven faired relatively well in terms of immunisation rates, stating that 93.8 per cent of 5-year-old children were fully immunised in 2012-13.

However, Gilmore MP Ann Sudmalis said the crackdown would "reinforce the importance of immunisation".

"As a mother and grandmother, I understand that parents want to be confident that they can send their children to childcare without the fear that they'll contract a potentially life threatening illness," she said.

For more information on child care assistance and family payments visit humanservices.gov.au