It has its own exquisite irony that, at a time when Tony Blair can't mention public services without mentioning in the same breath the importance of choice, women are to find their choices in childbirth subjected to new and stricter guidelines. They will have to fight harder to convince doctors that they need an elective caesarean as the National Institute for Clinical Excellence (Nice), the body responsible for establishing NHS guidelines, grapples with Britain's soaring caesarean rate.

The cynics say this is just about saving NHS cash with cheap vaginal births. Up goes the cry: "What about a woman's right to choose? Isn't it about time women got a break from generations of childbirth pain? What's wrong if all women, apart from a few lentil-eating types, end up opting for caesareans?" These seemingly reasonable arguments are only reinforced by the lopsided media coverage of the Nice guidelines in the past few days. Every newspaper, website and television news item has pounced on the subject as evidence of women choosing to fit in childbirth around their busy professional diaries. It's a "too posh to push" story - another stick to beat "the woman who wants it all" - and it gets instant primetime.

So first let's nail the myth that one in five of British babies are now born by caesarean because their mothers are squeezing the baby out between boardroom meetings: only 7% of caesareans are chosen without specific medical justification - that amounts to a few thousand women. It is this statistically tiny number of cases which is hijacking the entire debate.

Behind the latest controversy lies a bigger issue. The rising rate of caesarean births is an international phenomenon. America and Britain have a high rate of more than 20% of all births, but there are other countries which are much higher, such as Brazil (35%) and Puerto Rico (31.4%). At the same time, some northern European countries such as Norway and Sweden have brought their caesarean rates down to below 10%, apparently without any damaging consequences for child or mother. It is absurd to suggest that the driving force behind these patches of medicalised childbirth all over the globe is the boardroom mum.

Far more important are a range of factors; first, the growth of medical negligence claims, particularly in the US but also, increasingly, in the UK. Doctors and midwives get jumpy at any possibility of risk and whisk women into the operating theatre. Another major factor is that caesareans used to be an extremely dangerous procedure, but after major advances in anaesthetics, antibiotics and surgery, it has become much safer. Balance that against the risk of a baby being damaged in a long and painful labour and its hardly surprising that so many women choose the operating theatre.

But the consensus is that this assessment of risk is wrong. An extraordinary coalition from natural childbirth advocates right through to the Royal College of Obstetrics and Gynaecologists agree that the caesarean rate is too high and the rate of increase is alarmingly steep - another couple of decades and most births could be by caesarean. The World Health Organisation has suggested that the target rate for a country should be about 15% and even lower for industrialised, developed countries. Contrary to popular understanding, caesareans are not risk-free; there is the danger of infection, blood clots, risk to bladder and bowel. Besides, they make it difficult to have more than two children as well as the mother having to recover from major surgery at the same time as care for newborn. Studies have even found a link to increased infertility and subsequent stillbirths.

"Women have a right to choose but they need all the information to make that choice," says Dr Maggie Blott, an obstetrician at the Royal Victoria Infirmary in Newcastle, "When a C-section goes wrong, it's very much more serious."

The French obstetrician and pioneer of natural childbirth, Michel Odent, goes even further in a book published this month, The Caesarean, arguing that the medical procedure could have serious long-term consequences in impairing the mother-child attachment. He points to studies which have found links to a range of social problems from criminality to autism. Odent's arguments are controversial among obstetricians, but what is more widely accepted is an increased incidence of breathing problems in the babies delivered by caesarean. Twenty-two percent of Caesareans are performed because of concerns for the baby's welfare, another 20% are because the labour is not progressing. And here is the crux of the problem in Britain: we seem to be finding childbirth more difficult, not less. Despite - or perhaps because of - all the enormous advances in medicine which include the dramatic drop during the 20th century in infant and maternal mortality, the number of women having straightforward births requiring little or no intervention is declining.

Its not just the rising rates of caesareans we should be worrying about but the long, drawn-out labours which require forceps and ventouse. In fact, given the high risks to both mother and child of the latter, caesareans are sometimes safer. The right point to start this debate is not how do we reduce caesareans, but just why are women finding it so difficult to give birth. Not so much too posh, but why doesn't the pushing work?

Silverton points out that the proportion of first-time mothers is much higher today than 20 or 30 years ago, and inevitably, first-timers are more likely to be nervous and their births are more difficult. Fewer women have had first-hand experience of childbirth from mothers or sisters until it is their turn; the experience has been privatised. As women leave childbirth until later, they tend to be much more anxious and need a lot more antenatal reassurance - and they don't always get it.

Older women have often developed a strong sense of control in their lives in their work, and when they come to childbirth they see no reason to change. The birth-plans are drawn up even though childbirth might be one of those points in one's life where control and choice often turn out to be pretty illusory as events catapult an anxious mother into relying on the midwife or doctor.

For the past 20 years, there has been a steady stream of research showing how important it is for women that they feel relaxed, confident and in familiar surroundings during childbirth. Odent argues that rather than focussing our energies on bringing down the caesarean rate, we must reinstate the vital role of the midwife. "We have completely forgotten the basic needs of a woman in labour. She needs privacy, free from being observed or judged, and she needs to feel secure with someone to whom she is close."

Blott agrees, "We need to promote the normality of childbirth rather than medicalising it. Leave women to get on with it with experienced midwives."

That means a radical overhaul of how the NHS organises midwifery shifts so that the same midwife can stick with a woman throughout her pregnancy; it means more midwife-led units in hospitals. Most importantly, it means attracting thousands of trained midwives back into the job. They cite frustration with the increasing burden of paperwork as reasons for leaving; a study found that midwives spent only 15% of their time with the mother as they tried to keep ahead of record keeping and other duties. Get this central relationship with the midwife right and the caesarean rate will drop as a consequence. The concern is that the Nice guidelines could actually be dangerous - pressuring hospitals to allow painful drawn out births in order to keep their caesarean figures down.