A new study has suggested that the differences in opinion between doctors across England is the cause of varying rates of Caesarean sections carried out in the country.

A study published in the British Medical Journal shows the number of women undergoing the birth procedure ranges between 13.6% and 31.9% in the regions across England.

According to experts, the study of more than 620,000 births at 146 trusts shows the need for “informed surveillance” of why there are such difference.

The results did not support suggestions that increasing numbers of women are opting for Caesareans for non-medical reasons.

Researchers based at the Royal College of Obstetricians and Gynaecologists analysed births among women aged between 15 and 44 years during 2008.

Of the 620,604 births, almost one in four (24%) were delivered by Caesarean section.

A high proportion of women underwent the procedure because they had previously experienced a Caesarean (71%), a breech baby (90%), or serious medical complications (85%). The likelihood of having a Caesarean was also higher in older women.

But even taking into account medical reasons for the procedure, the report authors said there remained a considerable difference in the birth methods used based on medical judgements.

The report found the variation “probably reflects” the lack of a precise definition for foetal distress or dystocia - an abnormal or difficult birth - and differences in practices among professionals.

The authors called on trusts to examine the reasons for the regional variation and to consider how the consistency of care for pregnant women could be improved.

In an editorial, Marian Knight, from the University of Oxford, and Elizabeth Sullivan, of the University of New South Wales, said: “This research indicates, at a minimum, the need for more informed surveillance of Caesarean sections at a hospital, regional and national level.”

They said “a more detailed examination” of the variations was needed.

Caesarean section rates increased from 9% in 1980 to almost 25% in 2008/09.

Mervi Jokinen, practice and standards development adviser at the Royal College of Midwives (RCM), said: “At last we are discussing what is really behind the high rates of caesarean sections. I am also pleased that it clearly refutes the prevailing view that it is women requesting caesareans who are pushing up the rates.”

A Department of Health spokesman said: “Requests for Caesarean sections should be managed in accordance with the National Institute for Health and Clinical Excellence guideline recommendation that all clinical interventions, including elective Caesarean section, are only performed if there is clinical evidence of expected benefits to the mother or baby.

“A consultant must be involved in the decision to undertake any Caesarean.”