Antibiotics & premature labour

The results of a study [see news] involving researchers from Oxford University into whether women going into premature labour should be given antibiotics are published in The Lancet.

This is emotive stuff – one in eight babies in the UK is born prematurely and prematurity is the leading cause of death in the first month after birth – which goes someway to explain the leader in The Independent.

'As every pregnant woman knows, joy at the discovery that she is soon to become a mother turns rapidly to anxiety about how to protect her unborn baby… But now researchers have discovered that even the humble, and ubiquitous, antibiotic may pose a risk.'

As the piece admits, the results are complex, surprising and deserve to be understood. So let’s take a look.

Long-term effects
The research consists of a seven-year follow up of a clinical trial, ORACLE, into the use of antibiotics in women presenting with signs of premature labour without obvious infection.

The original ORACLE trial found that giving erythromycin to women whose waters had broken prematurely had benefits. No benefit or harm was found for those women in premature labour whose waters hadn’t broken.

The follow-up study wanted to see if there was any effect on the later health and development of the children. As Sarah Boseley in The Guardian reports, 'Scientists unexpectedly found that a small number of babies whose mothers were given antibiotics may have suffered damage.'

What was that damage?

The damage was only seen in those women given antibiotics whose waters hadn’t broken. Most of it was mild: there is an increase in parents’ reporting of impairment in their children, from poor eyesight, to experiencing difficulty walking around the block or struggling with day-to-day problem-solving. More worryingly however, there is a small increased risk of cerebral palsy (CP) in the children of this group of women, although rates of CP remain low.

No change to practice
BBC Online point out that, 'There is a link between antibiotic use and cerebral palsy, but this does not necessarily mean one is caused by the other.' They quote Professor Peter Brocklehurst of the National Perinatal Epidemiology Unit, Oxford University, who said: 'We have a suspicion that infection is implicated in premature labour. Antibiotics may merely suppress levels of infection to stop preterm labour, but the baby remains in a hostile environment.'

Because the results were unexpected, the Medical Research Council (who funded the work) is considering what further research could shed more light on these findings. 

Rebecca Smith, medical editor at The Telegraph, points out that: 'The results only apply to women who went into premature labour but whose waters had not broken and who had no obvious signs of infection.'

And in any case, 'It is thought that doctors have already stopped prescribing antibiotics in these situations.' So the results, surprising as they are, just reinforce existing practice and guidance.

Her concern is for the over 4,000 women involved in the original study, some of whom will have received antibiotics and some a dummy drug. They have now received letters and a helpline has been set up.

More importantly, antibiotics should still be used without any concern or fear in pregnant mothers with clear infections.

Balancing risk
Sir Liam Donaldson, the government’s Chief Medical Officer, has written to medical staff reinforcing this. His comments are reported by Jeremy Laurance inside The Independent: 'Antibiotics save lives and pregnant women with possible or obvious infections must be considered for treatment with antibiotics.'

Perhaps the real message is contained in a related editorial in The Lancet by Professor Philip Steer, of Chelsea and Westminster Hospital in London, and Dr Alison Bedford Russell, of Warwick Medical School: 'The lessons to be learned seem clear; contrary to popular opinion ('might as well give them, they don't do any harm'), antibiotics are not risk-free. There are good reasons not to give them in association with threatened pre-term labour unless there is clear evidence of infection.'

Your comments

There are currently no comments on this page.

• Post a comment