Knives are out

The latest figures suggest that one in seven pregnant women now has a caesarean delivery, with surgery rates increasing by 1% a year and varying between hospitals. The Royal College of Obstetricians and Gynaecologists has responded by launching a nationwide audit of all caesarean sections.

I work in a tertiary referral centre, where complex cases are transferred for expert care. Our caesarean rate is 22%, which is on the high side, but comparable with that of similar centres. I used to work in a maternity unit that was part of a district general hospital in Birmingham. The caesarean rate there was 13 to 14%. We didn't have so many high-risk transfers and it was a smaller unit. Also, perhaps because it dealt with fewer complicated cases, the thinking was less interventionist. The result was a low-tech approach.

There is a delicate balance in not letting the high-tech philosophy leak over to simple cases where intervention is less likely to be of benefit. We need to stick with the philosophy that normal pregnancies should be kept normal - without the use of unproven technology such as continuous electronic fetal monitoring in a low-risk labour.

The fact is that women who are confident about the birth of their baby and who have good support are less likely to have caesareans. So we should be worried about shortages of midwives and any move towards bigger hospitals. These are significant issues that affect virtually every mother-to-be.

Caesareans are an emotive subject for both medical professionals and childbirth campaigners. And as the operation becomes increasingly common, the debate over whether some of them are unnecessary becomes increasingly heated.

The decision to perform a caesarean delivery balances risk against benefit for mother and baby. As surgical and anaesthetic techniques improve, risk is reduced and the threshold for intervention falls accordingly. Thus, in an increasing number of circumstances, caesarean is the safest option available.

Meanwhile, perinatal medicine (medical care around the time of birth) has improved survival rates for younger and younger babies, making caesarean delivery appropriate when formerly it might not have been.

When I was training, if we found problems earlier than 28 weeks into a pregnancy, we wouldn't consider delivery, because the chance of survival was so poor. We are now facing those same problems, only at an earlier stage in the pregancy; we can offer something we couldn't before.

All this helps to explain the general rise in caesareans. But what it doesn't fully explain is the variation between hospitals - from about 14% to 24% in this country.

As I've said, tertiary referral centres receive high-risk cases that are more likely to require caesareans; other hospitals may serve high-risk populations, with more older mothers, for example; and in inner cities and major conurbations such as Birmingham and London, ethnicity and social deprivation play their part. But there are other factors at play.

One aspect is patient demand - what's been crudely referred to as the "too posh to push" debate. While there is certainly a middle-class group who want caesareans to suit their lifestyle, and others who see it as a quick and easy way of getting their baby delivered, there are also patients who have serious fears about the delivery process. I've had patients who have been sexually abused, for example, and have phobias about delivering the baby or even vaginal examinations.

The aptitude of individual doctors - their confidence at various procedures and their interpretation of inconclusive evidence - is also important. If a doctor feels uncomfortable with a particular mode of delivery - such as vaginal breech delivery - they might advise a caesarean. Some doctors consider vaginal breech delivery safe, others say it is unpredictable.

And, of course, the risk of litigation if the outcome is not ideal can also put pressure on a doctor to prefer caesarean delivery. The broader economics of caesareans are far from clear. It is commonly held that caesarean delivery is more expensive than instrumental vaginal delivery which, in turn, is more expensive than spontaneous vaginal delivery. But most studies have not accurately taken into account overheads such as the cost of on-call staff during vaginal delivery, long-term effects or medico-legal risk.

We do not know what the optimum caesarean rate should be and we probably never will. All we can say is that midwives and doctors have a duty to be up to date with practice and to impart their expertise in such a way as to enable pregnant women to feel in control.

• Harold Gee is a consultant in maternal-fetal medicine at Birmingham Women's Hospital