Births by emergency Caesarean may often be unnecessary, a group of senior obstetricians has warned.
Many emergency Caesareans could be avoided, experts say.
More than one in five of UK babies are born by Caesarean – a third of which are because labour is not progressing.
Writing in the British Medical Journal, the group says many operations could be avoided if senior doctors were present.
They quote figures showing that in many cases where labour was not progressing, use of forceps or a ventouse was not attempted or was unsuccessful.
The experts said better training and more recruitment of obstetricians were needed to address the problem.
Junior doctors make most decisions on whether an instrument such as forceps or ventouse should be used on a woman in delayed second-stage labour.
In more than half of emergency Caesarean cases, no attempt was made to use forceps or a ventouse for a normal vaginal delivery and, where an instrument was used, there was a failure rate of 35% for ventouse and 2% for forceps.
The experts said that although Caesareans were sometimes appropriate, many could be prevented by the attendance of a more skilled obstetrician.
The experts said: “A consultant obstetrician who performed a vaginal assessment was more likely to reverse a decision made by an obstetric trainee for a Caesarean and proceed to a safely conducted instrumental delivery.
“Without increases in junior doctors’ experience and recruitment into the specialty, the problems with second-stage Caesareans will rise.”
There are several dangers to emergency Caesareans, including the risk of major haemorrhage, bladder trauma and tearing.
Women are also more likely to have to stay in hospital for longer following the birth.
The authors added that, despite the inexperience of trainees, the UK was making “great strides” in terms of training and care.
But they said: “Nevertheless, it is essential to recognise the need for obstetricians to maintain and develop their skills if women are to be offered safe alternatives to Caesarean section when complications arise in labour.”
The experts were Chris Spencer, a consultant obstetrician at St John’s Hospital in Chelmsford, Essex, Deirdre Murphy, a professor at Trinity College at the University of Dublin, and Susan Bewley, a consultant obstetrician at Guy’s and St Thomas’s NHS Foundation Trust in London.
Dr Jo Hilborne, chairman of the BMA junior doctors committee, who is working in obstetrics, said: “This research shows why it’s so important for junior doctors to receive high quality training, and for consultants to be as available as possible.
“Given that junior doctors’ hours are going down, and medical training is in the middle of a major shake-up, it’s vital that new and better ways of training are developed.”
Virginia Beckett, of the Royal College of Obstetricians and Gynaecologists (RCOG), said the issue was complex.
She added: “We do have a problem with recruitment in obstetrics and gynaecology and we are working hard on that at the moment.
“Medical students and newly qualified doctors don’t find it as attractive as other specialisms because it’s intrusive on one’s personal life (such as unsociable hours).”
She said the RCOG had made recommendations for consultants to be available on maternity wards 24 hours a day rather than just on call as at present.