Cameron Loy, a GP practising in Lara, said there was a "common understanding that public hospital maternity units are under a lot of pressure and have been for a long time".

This was largely due to new suburbs being built without hospitals nearby, he said.

Dr Loy,  chairman of the Royal Australian College of General Practitioners, Victoria, said GPs discuss "all options" for pregnancy and birth with expectant parents.

"That being said, we encourage those with private cover to use it, mainly because of the increased access they will get to an obstetrician and hospital of their choice," he said.

Dr Loy isn't alone in raising concerns women are being encouraged to go to private hospitals or give birth far from home.

Northern Health runs Northern Hospital in the outer-northern growth area of Epping, where there were a record 348 births in July. 

Northern Health has warned that "without expanding its capacity and lifting its capability in the near future, it will reach its physical capacity by 2018", according to a recent report by the Victorian Auditor-General.

The report also said Northern Health had been forced to revise its modelling years ago after birth numbers reached forecasts three years earlier than expected.

In addition, Northern Health had been forced to increase its capacity to stop women from Melbourne's north overwhelming the Royal Women's Hospital in inner-city Parkville.

A spokesman said Northern Health had received $180 million in state government funding since May last year to expand capacity.

Northern Health was also working with the Andrews government "on a medium to long-term plan to support ongoing population growth and demand for our services", he said. 

Victoria has a policy that women should be able to choose where they give birth and be able to use local services if clinically appropriate.

But the Victorian Auditor-General's report from August concluded there was a "high level of uncertainty that birthing ... infrastructure will be provided when and where they are needed in areas of rapid population growth".

The uncertainty was largely due to "stakeholders' limited participation in the land use planning process, hospitals generally being built after a population boom rather than before" and underestimation of population growth by both local councils and the Department of Environment, Land, Water and Planning, the report said.

The Australian Bureau of Statistics will this week release birth figures for 2016, but there are indications last year was a boom one for bubs.

According to childcare company THINK Childcare, Victoria's birth rate grew 14.7 per cent last year to 84,404 – the state's highest birth rate on record.

What we do know is the number of births in Victorian public hospitals surged by 24 per cent in the decade to 2015-16, to almost 60,000. 

Over the same period, the number of births in public hospitals in Melbourne's northern growth corridor skyrocketed 68 per cent.

That's because Cardinia, Casey, Hume, Melton, Mitchell, Whittlesea and Wyndham councils on Melbourne's fringe have become home to a huge chunk of Melbourne's new residents since 2011.

And as Greater Melbourne's population exceeds 6 million by 2031, these areas are forecast to accommodate 42 per cent of the state's new citizens.

These areas are also estimated to see a whopping 86 per cent rise in children aged between newborn and nine over the same period, compared to a 25 per cent increase for the rest of Melbourne.

The good news is that babies born in Victoria have among the best chances of survival in the developed world.

The most recent review of births and deaths in the state has found that "despite the burgeoning rise in Victoria's population and consequent increases in the number of births, the outcome for mothers and babies continues to improve".

The Age