London is the worst place in the country to have a baby, according to the first review of maternity units in England.
Nineteen out of 27 NHS trusts in the capital were ranked as the poorest performers across a range of 25 indicators, ranging from tests during antenatal care to staffing levels on labour wards.
One in five of the 148 trusts surveyedwas found to be putting mothers and babies at risk by failing to carry out scans, discharging them too quickly or failing to follow up with postnatal visits.
All trusts were ranked on a four-point scale from best to worst in the review by the Healthcare Commission, the independent health inspectorate.
In response, the Health Secretary, Alan Johnson, announced extra funding rising over three years to £122m annually for maternity services and said the worst trusts would have to produce action plans.
"The NHS has much more work to do to ensure women receive the most modern maternity care. We will be holding the NHS to account," he said.
Anna Walker, chief executive of the Healthcare Commission, said "serious concerns" about maternity services had triggered three full-scale investigations by the commission and accounted for one in 14 referrals to its investigation unit on safety grounds.
"The review raises real concerns about performance in London. There are a number of factors that may have influenced these results such as lower staffing levels and the mobility and mix of the population. But London trusts need to rise to these challenge," she said.
Chelsea and Westminster NHS Trust is revealed as one of the worst maternity units. Other poor performers in London include St George's, St Bartholomew's and the London and Newham.
The highest standards were in the North of England, where three-quarters of the 44 trusts were ranked as top performers. The top three trusts in the country were Stockport, Gateshead and North Cumbria.
The NHS Confederation, which represents NHS trusts, said the review revealed "deep concerns". Nearly all women received an ultrasound scan but four out of 10 did not get all the checks recommended by the National Institute for Clinical Excellence (Nice).
Requirements for screening were raised in new guidance issued by Nice last April but nine out of 10 trusts are not meeting them, the review found. Trusts with the lowest number of midwives performed worst.
Gill Morgan, chief executive, said: "We believe that the choices mothers make about where they have babies... should drive patterns of maternity provision."