New evidence has emerged suggesting that the risk of birth defects associated with the antiepileptic drug (AED) lamotrigine may not be as great as previously believed.
Carried out by Ulster University, the research has cast doubt over previous conclusions pregnant women with epilepsy who take lamotrigine could be putting their unborn child at risk of cleft lip, cleft palate or clubfoot.
Although early studies of this drug associated it with an increased risk of cleft lip/cleft palate/clubbed foot, a number of subsequent studies have not supported this. To clarify these trends, the team looked at data regarding more than ten million births over a span of 16 years – more than double the size of the previous study. Of these, 226,806 babies were born with birth defects.
Results, published in the medical journal Neurology, showed that, within this group, there were 147 babies who had been exposed to lamotrigine within the first trimester of pregnancy who had non-genetic birth defects. Further analysis of the data revealed that babies with cleft lip, cleft palate or clubfoot were no more likely than infants with other birth defects to have been exposed to lamotrigine in the first trimester.
Study author Dr Helen Dolk, of Ulster University, said: “We cannot exclude a small risk, but we estimate the excess risk of cleft lip or cleft palate among babies exposed to the drug to be less than one in every 550 babies.
“Since excess risks of cleft lip or palate have been reported for a variety of AEDs, we recommend that for all mothers with epilepsy, whatever their drug exposure, special attention be given to examining the baby for cleft palate.”
Further studies may be needed to examine the specific doses of lamotrigine involved, in order to help clarify the precautions pregnant women need to take when seeking a safe method of treating their epilepsy.”
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