Natural childbirth is an experience that is becoming ever less familiar to British women. The number of Caesarean sections has risen sevenfold over the past three decades, and surgical deliveries now account for almost one in four births. Every year, the rate creeps up — from 22 per cent in 2002-3 to 22.7 per cent in 2003-4.

This trend alarms many observers, particularly members of the growing natural childbirth lobby. They note with concern that the World Health Organisation considers that only 10 to 15 per cent of births are sufficiently complicated to warrant a Caesarean, and point to evidence of the procedure’s risks.

Besides all the dangers that are always inherant in general anaesthesia and major surgery, the operation increases the chance of complications such as blood clots. Research has suggested a greater rate of stillbirth in subsequent pregnancies.

An Aberdeen University study published this week has also revealed a potential adverse effect on fertility.

Many women, it is often charged, are taking irresponsible chances with their own health and that of their children for the sake of convenience, comfort or fashion. They are “too posh to push” or “too vain to strain”, opting for the knife for cosmetic, social and even sexual reasons. Natural delivery, these voices argue, should be the norm.

Of course Caesareans have risks, and should not be undertaken lightly. But these have to be kept in perspective, and compared with those of natural childbirth. The Aberdeen research, for example, found that 66.9 per cent of Caesarean mothers went on to have another baby, compared to 73.9 per cent of those who gave birth unassisted. If there is an effect on fertility — or even on willingness to conceive again — it is a small one.

While it has certainly been transformed by modern medicine, natural childbirth is also a dangerous business. The evolutionary trade-off for humanity’s intelligence has been a head of unfortunately large dimensions — and this brings obstetric difficulties. Even in well-equipped western hospitals, women die in childbirth far more frequently than do gorillas or chimps in the wild. There are hazards to the baby too — one in 1,800 dies during labour.

Caesareans are not a panacea, but they can help. The risk of oxygen starvation, for example, is 80 per cent lower with a planned Caesarean section. And it is still the case that the vast majority of these operations are performed for medical reasons.

The notion that needless Caesareans, undertaken for trivial reasons, constitute an important or disturbing social phenomenon is a myth. Only 7 per cent of all C-sections, or about 9,000 births a year, are purely elective. Disquiet about this often smacks of the condescending attitude of anti-abortion groups who claim women have a cavalier attitude to terminations. As with abortion, there are as many decent explanations for the decision as there are women who take it.

Many probably do want to trade the pain of childbirth for the longer period of recovery that comes with a Caesarean — but is that an illegitimate choice? Others will be worried about the possibility of an episiotomy and prefer a cut in their abdomen to one in their genitals. Is that trivial or unreasonable?

While it is right to think critically about Caesareans, the idea that we should always be aspiring to reduce them is misguided. What matters most is that the risks and benefits of both surgical and natural births are presented fairly and fully so that a woman’s decision has her informed consent. If that leads to fewer elective Caesareans, or to more of them, then so be it. But when there is no compelling medical reason to go either way, the best placed person to make the choice is the mother herself.

Mark Henderson is the Times science correspondent

Times Recommends

• Donor organ allowed child’s own heart to heal
• Michael Jackson: Not the final chapter
• Brüno toned down for 15 rating