Giving antibiotics to women at risk of premature birth may increase the chance of their babies suffering from cerebral palsy and other conditions according a leading doctor at the Chelsea and Westminster Hospital.
Professor Philip Steer has warned antibiotics must not be overprescribed to mothers after the publication of findings of a groundbreaking seven-year study.
Writing in the medical journal The Lancet he said: "The lessons to be learned seem clear; contrary to popular opinion, antibiotics are not risk free and there are good reasons not to give them in association with threatened pre-term labour, unless there is clear evidence of infection."
Prof Steer's comments come in the wake of a global study conducted between 1994 and 2000 into possible long-term damage to babies caused by antibiotics.
The research, called the ORACLE trial and carried out over the time gap to assess long-term effects, found evidence that the babies of some mothers who were prescribed two antibiotics to delay premature births suffered problems such as visual impairment and cerebral palsy.
The results of the follow-up study on the mothers have startled the medical community. The antibiotics - erythromycin and co-amoxiclav - were previously thought to delay the onset of labour and reducing the rate of infection among babies. Scientists now say doctors should not prescribe antibiotics in cases of premature labour where the mother's waters have not broken.
Sara Kenyon from the University of Leicester, who led the study, said: "Before the trial, there was some evidence of short-term benefits of antibiotics in premature labour, but we did not know what the long-term outcomes would be. It's thanks to each and every one of the mothers who were involved in the original trial and seven-year follow-up study that we now have the evidence to inform clinical practice."