In a paper to be published in the Medical Journal of Australia on Monday, the dean of medicine at Bond University Peter Jones argued placing children in out-of-home care can do more harm than good in some cases.

Professor Jones accepted the suggestion of creating public policies to limit the size of families among disadvantaged communities was controversial but essential given the ballooning number of children in care which has risen from 14,000 to 43,399 in the past two decades.

"We need to ask politically charged questions, such as should we be developing policies that encourage disadvantaged families to have fewer children," he said.

The pediatrician said parents who are unable to care for their children should not be given incentives to have more.

"In 2017 the majority of women are not going to have more than two children," he said.

"If that's the societal norm, why are we having uncapped child support subsidies given to people in socially disadvantaged situations? Our current system is set up such that we give more and more welfare. That doesn't lift people out of poverty."

However, CEO of the CREATE Foundation Jacqui Reed said developing policy around social engineering was not feasible.

"I think it's an offensive statement to make, and a really simplistic one and it again blames the victim.

"I have no idea how he would even begin to implement that apart from using punitive measures around payment - I just don't know how he would imagine he would be able to facilitate that," Ms Reed said.

The head of the Association of Children's Welfare Agencies, Andrew McCallum agreed such a solution was a "slippery slope".

"[That] disadvantage means that you are then subject to further social policies that don't apply to the rest of the population, I think that's a very slippery slope to go down," he said.

"There's a whole range of other things that actually underpin why people are socially disadvantaged and to draw a straight line between that and the number of children [people have] is probably missing many of the other causal factors."

Ms Reed suggested addressing those causal factors, which tended to stem from drug, alcohol and mental health problems, would be a more effective way of seeing parents were able to properly care for their children.

"If we had better mental health services and we had much more of a focus on early intervention and family support, then we wouldn't be looking at these children being tangled up with the system long term," she said.

Prof Jones also proposed providing better early intervention for vulnerable families in the form of education and employment opportunities.

"You need to invest in people so they become independent," he said. "They don't become independent by having multiple children to multiple partners who get taken away."

His views mirror the Federal Government's "investment approach" to welfare with its Try, Test and Learn Fund targeting young parents, along with young carers and young students at risk of long term unemployment.

"We know that these are consequences of people being disadvantaged so let's deal with the disadvantage rather than the actual consequences of the disadvantage, let's make them more advantaged," Mr McCallum said.

Prof Jones believes out-of-home care policies are failing children, with evidence showing young people who have been in care have poorer overall health and lower education than average.

"The fundamental reason for placing children in out-of-home care is because we believe they will be safer and they will have a better life than if they remained with their families," he said.

"There's not a lot of evidence to back up that hypothesis even though its that hypothesis that guides the decision to put children in out of home care."

The NSW government spends more than $1 billion a year on out-of-home care but has introduced moves to reduce the number of young people in care including promoting adoption and putting $90 million over four years towards interventionist programs to support families where there has been abuse and neglect.