A pain-relieving drug could help halve the number of women needing epidurals during labour, a study has said.

Scientists say remifentanil, which is rarely offered during labour, is more effective at relieving pain than the more commonly-used pethidine, which is given to more than 250,000 women each year.

A study involving 400 women found that half as many of those who were given remifentanil needed a subsequent epidural, compared to those who were given pethidine.

Epidurals, which are given as injections around the spinal chord, provide effective pain relief by blocking sensation, but can often lead to a forceps or vacuum delivery and more problems for mothers later down the track.

Lead author Dr Matthew Wilson, from the University of Sheffield, said the study’s findings “challenge the routine use of pethidine for pain relief during labour”.

He added: “Previous studies have shown that at least one in three women given pethidine to manage pain during labour require a subsequent epidural as the drug is not always effective.

“It also has unwanted side effects such as sedation and nausea for the mother, and it may pass into the baby’s bloodstream through the placenta.

“Remifentanil reduced the need for an epidural by half and there were no lasting problems for the mothers and babies in our trial, although the effect of remifentanil on maternal oxygen levels needs to be clarified in further studies.”

Half of those involved in the trial, which was conducted across 14 maternity units, were given remifentanil during labour, which women could administer themselves by pressing a hand-held device when they felt pain.

The rest were given pethidine, which was given as an injection up to every four hours.

Some 19% of those in the remifentanil group went on to have an epidural, compared to 41% in the pethidine group.

Women given remifentanil rated their pain as less severe, and were also less likely to need forceps and vacuum during labour than women given pethidine (15% vs 26%).

However, experts have cautioned that further studies will be needed before any changes in clinical practice.