The gas-air mixture is stronger than anything being used in maternity hospitals, and early clinical trials indicate that women find it more acceptable than pain-relieving alternatives.
Dr John Ross and Dr Mike Tunstall, from the Department pf Environmental and Occupational Medicine at Aberdeen University medical school, developed the gas which is a mixture of nitrous oxide and oxygen (known as Entonox) and small amounts of an anaesthetic agent, isoflurane.
Dr Ross said that during a painful labour, women are given an injection of morphine-like drugs, then Entonox gas.
'Most women manage fine but there are quite a large number of mothers for whom the pain becomes intolerable,' he said.
'They are then offered an epidural but not all maternity hospitals have this facility. The pain is then conventionally dealt with by giving as much morphine as required to get the mother through the experience, which is pretty grim.'
Dr Ross, who has worked on the new gas for five years, said that morphine can depress a baby's breathing and it may be necessary to administer an antidote. 'The great advantage of a gaseous pain-killer is that it is breathed in and breathed back out again and does not hang around to affect the baby.'
The gas, which can be self-administered, can also be used in other medical procedures such as the removal of drainage tubes after surgery.Reuse content