A new study from researchers at University College London reports a slightly increased risk of epilepsy or cerebral palsy for babies whose mothers take macrolide antibiotics during pregnancy.
The study, from the UCL Institute of Child Health (ICH), was published online in PLOS One on March 25, 2015. The study follows evidence of harm associated with prenatal antibiotics provided by a single large trial (n > 4,000) of prophylactic antibiotics for women in preterm labor. The authors, led by Ruth Gilbert, professor of clinical epidemiology at ICH, have determined the risk of cerebral palsy or epilepsy in children whose mothers were prescribed antibiotics during pregnancy using a cohort of 195,909 women, Pharmaceutical Journal reports.
Gilbert points out that patients could face significant harm from an infection and this could be more significant than the risk posed by antibiotics, but she says the study findings add weight to concerns over this group of antibiotics. Gilbert says, “we need to consider whether we should recommend alternatives,” according to Pharmaceutical Journal.
The children were followed from birth to a median of 3.6 years. The researchers found no association between mothers who had been prescribed any type of antibiotic and cerebral palsy or epilepsy, but did find a slightly increased risk of cerebral palsy or epilepsy in the children of mothers who had been prescribed macrolides compared with penicillin. The incidence of cerebral palsy or epilepsy in children whose mothers took macrolides was 254.6 per 100,000 child-years-at-risk, compared with 143.6 in children whose mothers took penicillin, Pharmaceutical Journal reports.
June Raine, director of vigilance and risk management of medicines for the UK’s Medicines and Healthcare products Regulatory Agency (MHRA), urged caution in considering the study’s findings. “The suggestion of a risk with the use of macrolide antibiotics during pregnancy should be treated with great caution,” Rain warns. “The conclusion is based on small numbers and incomplete data such as information on the type and seriousness of the infection. The MHRA has sought independent expert advice which confirms that the study is insufficient to suggest that use of macrolides in pregnancy is associated with a particular risk.”
But Gilbert counters that the study’s findings should be viewed in context. “There is now a large body of evidence of adverse effects of macrolides in different populations, during pregnancy and in adults,” according to Gilbert. “There are three very large database studies in adults showing an association between macrolides and cardiac deaths and cardiac events.” She called this a “very rare, low risk,” but still a risk.
A 2005 Swedish study reported a link between erythromycin use by pregnant women and cardiovascular malformations in infants. Based on these findings, several Scandinavian countries recommended against prescribing the drug to pregnant women, according to Pharmaceutical Journal. Gilbert points to “an accumulation of signals here that need to be looked at by a medicines regulator and by people who write the guidelines.” The question, Gilbert says, is whether the evidence is strong enough for patients to be informed about it, particularly since there are suitable alternative treatments.