The government has promised mothers choice by 2009
Some English hospitals should be stripped of doctor-led maternity care and specialist children's services, a government adviser says.
Dr Sheila Shribman, the children and maternity tsar, calls for regional super-centres instead.
Hospitals that lose maternity units may get midwife-led services and more support for home births will be provided to give women greater choice.
Dr Shribman said the move would improve care, not damage it as critics say.
Some have argued that hospital cuts are being driven by NHS deficits - the health service finished last year over £500 million in the red.
But Dr Shribman said EU restrictions on working hours meant specialist services could not be safely provided in every local hospital.
She said it would be better to have the best doctors on hand round-the-clock in regional centres.
She said: "I do not believe the changes I am proposing are about the budget.
"I understand people feel anxious when they think they might lose something."
She added: "Women will not be losing access to a consultant should they need one, it might not just be down the road."
The prospect of hospitals losing services has sparked anger among the public with demonstrations seen up and down the country.
The government has already floated the idea of taking A&E and specialist heart services away from some hospitals.
Many NHS trusts are already drawing up plans to re-design services.
Dr Shribman's report suggested networks of care could be created for maternity services, intensive neo-natal care and paediatric and child cancer services.
She said regional centres providing this specialist care would be supported by enhanced community services.
These could include midwife-led birth centres, either in local hospitals or community clinics.
There would also be better support for home births.
The government has promised to give women a choice of where they give birth by 2009.
But the Royal College of Midwives (RCM) has said another 10,000 midwives would be needed on top of the 24,000 already working in England.
Dame Karlene Davies, RCM general secretary, said real choice was good news for women.
But she said: "We need more than fine words to ensure that this vision is translated into maternity services that provide not only choice but one-to-one care from the same midwife throughout pregnancy."
Mary Newburn, of the National Childbirth Trust, said: "Just because services have been organised around hospitals in the past doesn't mean this is the best or only way of providing care."
Dr Shribman refused to be drawn on how many regional centres would be needed, but the Conservatives have identified 43 maternity units at risk - a fifth of the total.
Shadow heath secretary Andrew Lansley said: "Government nationally seems to be saying that everything has got to change and smaller units have got to be shut down, while locally, Labour ministers say they don't believe it and it's not justified. There's a hypocrisy in that."
Several members of the government, including Ivan Lewis, the health minister with responsibility for maternity services, have campaigned against cuts in their constituency.
Liberal Democrat health spokeswoman Sandra Gidley said: "The government's drive towards regionalised care is back to front and driven by financial panic."