Babies born in affluent parts of London are up to twice as likely to delivered by Caesarean section than those in the rest of the country, figures show.

Some women in more wealthy areas are still thought to be “too posh to push”, choosing to have a planned Caesarean over a natural birth, despite the increased risks to mother and baby.

Figures from the NHS Information Centre show that almost one in four babies in England (24.6 per cent) were delivered by Caesarean (C-section) in 2008-09.

This was no change on the previous year, but is still double the rate recommended by the World Health Organisation, which says the rate of C-sections should not exceed more than one in eight births.

Although some Caesareans are medically necessary, the procedure is considered a major operation for the mother and is associated with a greater chance of stillbirth and other health problems for the baby.

Women in Chelsea and Westminster last year were twice as likely to have their babies delivered by Caesarean section as those born in Nottingham, which has the lowest rate for C-sections in the country.

However, emergency Caesarean rates continue to outnumber planned operations.

The overall birthrate is also continuing to rise, putting pressure on NHS services that midwives’ and doctors’ leaders say are already overstretched.

There were more than 652,000 deliveries in NHS hospitals in England in 2008-09, a rise of 0.4 per cent on the previous 12 months. The birthrate across Britain has risen by about 16 per cent since 2001 and is now at its highest level since the 1970s.

There were nearly 155,000 C—sections recorded in 2008-09. About 40 per cent of these were carried out as a planned procedure, and about 60 per cent were unplanned operations.

Chelsea and Westminster NHS Foundation Trust had the highest percentage of C-sections (33.3 per cent of all births), around half of which were planned operations.

This was more than double the rate for Sherwood Forest Hospitals NHS Foundation Trust in Nottinghamshire (15.8 per cent).

London overall has the highest rates in England for the procedure, with 27.1 per cent of all deliveries being C-sections.

But as well as patient choice, the increased rates are also thought to be due to a greater proportion of foreign-born mothers giving birth in the capital.

Foreign-born mothers are more likely to need the procedure because in some cases doctors have less medical information about them, so they are regarded as more at-risk. Mothers who have other health conditions or leave it till later to start a family are more likely to experience complications at birth which require an emergency C-section.

Over a fifth of babies born at Newham University Hospitals NHS Trust in east London were born by emergency Caesarean, while planned operations — at 7.3 per cent of all births — were below the national average.

Cathy Warwick, the general secretary of the Royal College of Midwives, said that regional variations could only partly be explained by the needs of different populations. The attitudes of doctors and of expectant mothers also played a role, she said.

“It is disappointing that we are not seeing a drop in the Caesarean-section rate, and worrying that there are such wide regional variations, given that there is general agreement that Caesarean-section rates are higher than they need to be. This is a major operation, with potential complications for women and their babies.”

Studies have found that mothers who have a Caesarean delivery have more than triple the chance of needing a hysterectomy after their next pregnancy.

The operation is also linked to higher risks for both mother and baby, including increased risk of death, blood clots and infant breathing problems.

Ms Warwick added: “There is now general acceptance among maternity services professionals that the Caesarean-section rates are too high and that some women and their babies are being subjected to unnecessary [medical] interventions.”

The lowest rate of emergency Caesareans was seen at Wrightington, Wigan and Leigh NHS Foundation Trust, at 9 per cent, while Peterborough and Stamford NHS Foundation Trust saw the lowest rate of elective operations, at just 5.6 per cent of all births.

Chelsea and Westminster said that its Caesarean rate was boosted by women who paid privately for treatment.

“If these figures are excluded, Chelsea and Westminster Hospital’s rate of Caesarean section is 26 per cent, which is very comparable to other units in London,” said a spokesman.

“Chelsea and Westminster Hospital is also a regional referral centre for sick babies, many of which are delivered by Caesarean section, and we provide a very different and more complex level of care than a district general hospital.”

A Department of Health spokesman said: "In line with the National Institute for Health and Clinical Excellence guidelines on Caesarean sections, we recommend that clinical interventions, including elective Caesarean section, are only performed if there is clinical evidence of expected benefits of these to the mother and/or baby and that a consultant is involved in the decision to undertake any Caesarean.

“DH is focused on improving support for women with the aim normalising birth and reducing the number of Caesarean sections needed or wanted, for medical or emotional reasons. The NHS Institute of Innovation and Improvement are working with SHAs to promote keeping first pregnancy and labour normal, supporting vaginal birth after a previous caesarean and elective caesarean section while maintaining safe outcomes for mothers and babies.”

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