That is the view of Tasmanian demographer Amina Keygan, who believes it is likely many people will put off having children because their finances have been hit by the coronavirus-driven economic crash or they are worried about their financial prospects.

"The fact is, people are likely going to put off having children for the same reasons they are putting off a lot of major life decisions ..." Dr Keygan said on Tuesday.

"There's an incredible amount of uncertainty, both from the economic and social perspectives, because of COVID.

"If governments wanted to support people in having more children in this period, there are pro-natal policies they could implement: for example, more expansive paid parental leave ... free childcare, free early education and high quality access to early education."

Mr Frydenberg is keen for the birth rate to increase to help stave off the economic damage caused by rapidly slowing population growth.

With the crisis slashing immigration from overseas, Australia's population growth rate is expected to slump to 0.6 per cent in the current financial year.

Mr Frydenberg said that would be the lowest rate since 1916-17.

" ... I won't go as far as to say, like (former treasurer) Peter Costello, 'One for the mother, one for the father and one for the country,' but I can say that people should feel encouraged about the future and the more children that we have across the country, together with our migration, we will build our population growth and that will be good for the economy," Mr Frydenberg told the National Press Club on Friday.

"I think the best thing we can do to encourage more children being born across the country is obviously to create a strong economy for them to be born into."

Dr Keygan - also a state Labor staffer and Burnie councillor - said there was a disconnect between those words and the government starting to roll back supports for parents, such as the free childcare introduced during the pandemic.

She said workforce prospects, secure employment and housing were other "really important prerequisites for people to engage in childbearing".

Dr Keygan said women had been disproportionately affected by the coronavirus recession job losses, while University of Melbourne research had shown women still did a disproportionate amount of unpaid caring work within families, and the pandemic had increased that.

She said calling for more babies in those circumstances without additional support smacked of a lack of understanding of what women and couples needed to have more children.

Dr Keygan said she did not expect a dramatic drop in fertility rates in Tasmania and nationally, but she did expect a "delay in fertility", as people put off having babies because of the uncertainty.

"We might see a bounceback effect once things have settled down," she said.