Labour painkiller causes persistent backache

Women who are given epidurals for pain relief during labour are more likely to experience long term backache.

A study of nearly l2,000 women delivering at the Birmingham Maternity Hospital published in the British Medical Journal found a "causal" association between backaches occurring after delivery and the use of an epidural anaesthesia during labour. An epidural anaesthetic, administered by a needle injected into the subarachnoid space of the spine, allows a woman to remain awake during labour but numbs the entire lower half of the body. It is widely used during difficult deliveries (for, say, abnormal foetal presentation, a long second stage or forceps deliveries) or "elective" caesarean sections. In some quarters it is touted as a risk free way to have a "painless" labour.Of nearly 5000 women who had epidurals, 903, or l8.9 per cent, reported having backaches develop within three months of their deliveries and persisting for at least six weeks. This compares to l0.5 per cent of the maternal population without epidurals who complained of long term backache.

"Women who had epidural anaesthesia were much more likely to suffer from subsequent newly occurring long term backache even when allowance was made for all the other associated factors," said the report. "These other high risk characteristics were not themselves directly responsible for the subsequent backache; the prediction seemed to be almost entirely a function of having epidural anaesthesia."

The report hypothesized that the backaches were caused by the combination of being anaesthesized while having to labour; a woman might place stress on her spine that she might not be aware of because she has no feeling. "In addition, movement under epidural anaesthesia generally requires assistance, so that a woman could remain without immediate discomfort or complaint for some hours in a potentially damaging position," the report concluded.