GPs warned over pre-term risks in use of antibiotics
GPs should not prescribe antibiotics to pregnant women for bacterial vaginosis because of the risk of pre-term birth, UK researchers warn.
Their study found preventive use of metronidazole in pregnant women at high-risk of pre-term birth had the opposite of the intended effect significantly increasing premature births.
The steering committee halted the trial after finding 21 per cent of women taking metronidazole delivered before 30 weeks compared with 11 per cent taking placebo.
Baby charity Tommy's, which funded the research, estimated around 1,000 babies might be born prematurely each year because of the drug.
Researchers warned the study not only ruled out prophylactic use of antibiotics, but questioned their use in women testing positive for vaginosis contradicting guidance from the Royal College of Obstetrics and Gynaecology.
Study leader Professor Andrew Shennan, professor of obstetrics and gynaecology at St Thomas' Hospital, London, called the findings 'worrying'.
He said: 'There's no evidence antibiotics should be used at all. The worrying thing is so many women might be getting antibiotics and we would be doing them more harm than good.
'If someone comes to me with vaginal discharge, personally I would not prescribe metronidazole because I don't think the benefits outweigh the risks.'
Dr Brian Crichton, a GP in Solihull, Birmingham, and honorary lecturer in therapeutics and pharmacology at the University of Warwick, said the results flew in the face of current GP practice.
'It creates concern for doctors and patients. We need a clear consensus from the Medicines and Healthcare Products Regulatory Agency as soon as possible.'
The study, published early online in the International Journal of Obstetrics and Gynaecology, screened 900 women with at least one risk factor for pre-term birth in the second trimester of pregnancy.
Researchers randomised those who tested positive for fetal fibronectin a marker of risk to a one-week course of metronidazole or placebo.
By 37 weeks, 62 per cent of women on metronidazole had given birth, but only 39 per cent of those on placebo.
The MHRA said it would 'carefully review' the new study.