More than 20 per cent of babies born in England and Wales are now delivered by caesarean section.
The National Sentinel Caesarean Section Audit - the first detailed analysis of such births in the UK - shows that caesareans have increased by 400 per cent since 1970, and have doubled during the past decade.
Women with a previous caesarean, a breech birth or premature labour were more likely to have the operation, as were older women and those from ethnic minorities.
The audit findings have prompted calls for urgent guidelines for physicians and midwives to reduce the number of unnecessary caesarean births. The World Health Organization recommends a rate of caesareans of 10 to 15 per cent of births. This study shows that, in the UK, the procedure is used in 21.5 per cent of all births, one of the highest rates in Western Europe (BMJ, 2001; 323: 951).