Eli's birth, at Newcastle Private Hospital, came before changes to the Federal Government's Extended Medicare Safety Net increased the cost of out-of-hospital care for private patients.

Previously a patient would be reimbursed 80 per cent of out-of-pocket expenses for out-of-hospital care after reaching the safety net threshold (of $562.90 for concession cardholders and people receiving Family Tax Benefits, and $1126 for all others).

But the Government has placed a cap on most obstetric services including antenatal visits and scans.

The National Association of Specialist Obstetricians and Gynaecologists estimates that, on average, pregnant women expecting to deliver their babies after May 20 will be almost $1000 worse off.

The association's president, Dr Hilary Joyce, said many families would not be able to afford the additional out-of-pocket costs.

"Many families do not realise what has happened to the cost of obstetric care since January 1 and so may not be financially prepared for it," Dr Joyce said.

Having to find another $1000 to pay bills associated with the birth would make a big difference to the Hopes. .

It might mean the difference between choosing the public or the private system, despite the fact they have private health insurance.

It might also affect how long they could afford for Mrs Hope to stay home with the new baby, when her paid maternity leave runs out in three months.

The changes would force some mothers-to-be into the already overwhelmed public hospital system, Dr Joyce said.

"We are looking forward to working with [Federal Health] Minister Nicola Roxon to find a better way to save money for taxpayers without hurting Australian women creating families," Dr Joyce said.