It also highlighted a wide variety in the rate of Caesarean births throughout the UK.

Caesarean rates

England and Wales - 21.5% North Eastern - 19.3% North Western - 19.6% East Midlands - 20.4% West Midlands - 21.8% Eastern - 21.4% London - 24.2% South East - 22.6% South West - 19.4% Wales - 24.2% Northern Ireland - 23.9%

The study, carried out by the Royal College of Obstetricians and Gynaecologists on behalf of the Department of Health, involved an audit of every maternity unit in England and Wales over a three-month period between May and July of this year.

Guidelines

The results will be used by the National Institute of Clinical Excellence (NICE) to devise clinical guidelines on Caesarean deliveries and to develop the National Service Framework for Children.

Thirty years ago just 3% of babies were born by Caesarean section in the UK.

The World Health Organisation recommends a Caesarean rate of between 10% and 15%.

Of all Caesareans carried out in England and Wales the main reasons included fetal distress (22%), lack of progression during labour (20%), previous Caesarean (14%) and a breech baby (11%).

More than 60% of all Caesarean sections carried out in England and Wales were classed as an emergency procedure.

If you have major abdominal surgery there can be complications

Mary Newburn

Up to 7% of all Caesareans were performed for no specific medical reason, so raising fears that many women are opting for the surgical procedure to fit in with busy lifestyles.

Health minister Jacqui Smith welcomed the report: "The audit shows that there are significant variations in the Caesarean section rate in different parts of the country and among different sections of the population.

"Some of these variations may be due to women having more choice about their maternity care and childbirth but many are too great to be explained by choice alone and we need to know more.

"The next stage of the research will look at why these variations exist and will assess the best way to tackle inequalities in the system."

'Informed decisions'

Obstetricians are concerned at the high rate of Caesareans and want to raise awareness among women about the risks.

Mary Newburn warned of the dangers of C-sections

Professor Bill Dunlop, president of the Royal College of Obstetricians, said: "We know the Caesarean rate has been on the increase over the last decade and we all need to understand the implications of this.

"Women, midwives and doctors still need more information about the chance of complications arising from this major abdominal surgery so that women can make informed decisions about their delivery."

Complications include hysterectomy, post-natal depression and even death.

Other factors contributing to the high increase in the number of Caesarean births included the size of the hospital, the availability of a neo-natal intensive care unit and the number of midwives on duty.

The audit showed that while the majority of units provided one midwife per woman in labour, in 5% of units only one midwife was allocated for up to three women.

Earlier this year the Royal College of Nursing (RCN) called for the number of Caesarean births to be cut, after it was revealed that in some UK hospitals the rate of Caesarean births was as high as 40%.

Complicated

The National Childbirth Trust (NCT), which participated in the study, believes the reasons for the increase in the number of Caesarean births are complicated.

But Belinda Phipps, chief executive of the NCT, said there was no evidence to suggest that a Caesarean section rate above 8% did anything more for neo-natal survival.

Her colleague Mary Newburn said: "Having a Caesarean section does not mean a painfree birth.

"One of the things that is often said is that if you have a vaginal birth you have the pain before the baby, and if you surgery you have the pain afterwards.

"If you have major abdominal surgery there can be complications, and that is not something that people should discount lightly."