Prescribing women a new drug called remifentanil to help manage their labour pain may halve the need for an epidural than the traditional pethidine, claims a study.

The study, published in the Lancet, suggested that using remifentanil instead of pethidine could reduce the need for epidurals, instrumental deliveries and consequent morbidity for large numbers of women worldwide.

Epidurals -- injections of pain relief drugs around the spinal cord -- provide effective pain relief but increase the risk of needing instrumental delivery (forceps or vacuum) during birth. It can also increase the risk of trauma and long-lasting problems for the mother, such as incontinence and sexual dysfunction. Our findings challenge the routine use of pethidine for pain relief during labour," said lead author Matthew Wilson, from Britain's University of Sheffield. 

"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," he added. Remifentanil is rarely offered routinely in labour and its use restricted to women who cannot receive an epidural for medical reasons (such as blood clotting disorders). 

Conversely, pethidine has been in widespread use since the 1950s, even after long been known not helpful to all women.The study included 400 women aged over 16 years old who were giving birth after 37 weeks. Only half as many women in the remifentanil group went on to have an epidural (19 per cent) than in the pethidine group (41 per cent).These women rated their pain as less severe and also had less likely to need forceps and vacuum during labour than women given pethidine (15 per cent vs 26 per cent).

However, remifentanil was associated with twice as many mothers having low oxygen levels than pethidine (14 per cent vs 5 per cent.
But, despite this increase it did not cause any negative effects for the mother or baby, but more research in larger groups will be needed to confirm this, the researchers said.