A STUDY led by a specialist at Poole Hospital has made important new discoveries about two types of pain relief commonly given to women during labour.

Researchers at Poole and Bath recruited 484 women for a trial comparing the effectiveness and side-effects of diamorphine and pethidine.

They found that diamorphine gave much better pain relief, but extended delivery time by about 82 minutes. Further investigation will be carried out to find out why.

Previous research had shown that pethidine did not give effective pain relief in labour and had side-effects for mother and baby.

But the trial found no major differences between the two drugs for side-effects in mothers, including nausea and vomiting and blood oxygen levels.

There were also little difference between the two drugs in the number of babies needing resuscitation or having low Apgar scores.

Apgar is the scale used to assess the baby’s overall condition at one minute and five minutes after birth.

Babies born to mothers who had been given pethidine during labour were more sedated two hours after delivery than babies whose mothers had diamorphine.

The use of diamorphine for women in labour has increased over the last decade in the UK. The study said women receiving it were more satisfied with their pain relief than those given pethidine.

The chief investigator of the trial was Professor Michael Wee, a senior consultant anaesthetist at Poole Hospital.

“Women choosing to have either drug should be informed of these findings, which are new and significant. There is a choice to be made based on the information,” he said.