WASHINGTON – Exposure to antiepileptic drugs via breast milk during infancy was not associated with adverse neurodevelopmental effects at age 6 years in the prospective, observational Neurodevelopmental Effects of Antiepileptic Drugs study.
In fact, overall, the children in the study who were exposed to antiepileptic drugs (AEDs) via breast milk exhibited higher IQ and Verbal Index scores than did those who did not breastfeed (adjusted mean IQ scores of 108 vs. 104, and adjusted mean Verbal Index scores of 105 vs. 102, respectively), Dr. Kimford J. Meador of Stanford (Calif.) University reported at the annual meeting of the American Epilepsy Society.
Dr. Kimford J. Meador
Of 181 children in the multicenter study, 43% were breastfed for an average duration of 7.2 months. AED exposures included carbamazepine, lamotrigine, valproate, or phenytoin. IQ scores were higher for breastfed vs. nonbreastfed children for each of these drug groups except phenytoin (108 vs. 105; 114 vs. 110; 105 vs. 107; and 105 vs. 94, respectively). Significant independent variables predicting age 6 IQ included maternal IQ, AED group, AED dose, periconceptional folate, and breastfeeding.
Scores on cognitive domains other than the Verbal Index, including Nonverbal Index, Memory Index, and Executive Index, also were slightly higher for breastfed vs. nonbreastfed infants, but the differences did not reach statistical significance, Dr. Meador said.
The Neurodevelopmental Effects of Antiepileptic Drugs (NEAD) study, conducted in the United States and the United Kingdom, included pregnant women with epilepsy who were on AED monotherapy. The women were enrolled between 1999 and 2004, and they continued taking AEDs after delivery. Their children were assessed at age 6 years via the Differential Abilities Scales (DAS) and other measures of cognitive ability. Mean scores were adjusted for maternal IQ, AED group, AED dose, and periconceptional folate.
NEAD follows an earlier study that looked at outcomes in the children at age 3 years (Neurology 2010;75:1954-60). That report also demonstrated that children exposed to AEDs via breast milk experienced no adverse neurodevelopmental effects, but outcomes at age 6 years are considered more predictive of school performance and adult ability, Dr. Meador explained during a press briefing at the meeting.
The findings are among the first to evaluate neurodevelopmental outcomes following AED exposure via breast milk, and although they don’t provide a definitive answer about the safety of AED exposure via breast milk, they do provide reassurance for concerned mothers weighing the well-known benefits of breastfeeding with the potential risks of infant AED exposure, he said.
Dr. Meador said that he – along with the NEAD study group – recommends breastfeeding for women who were already taking AEDs during pregnancy, but noted that the findings do not address those who begin taking AEDs after delivery.
"Our recommendation is based on the known positive effects of breastfeeding, the results of our study, and unsubstantiated theoretical risk, and theoretical reasons why breastfeeding on AEDs would not offer additional risk," he concluded.
NEAD was supported by grants from the National Institutes of Health to Dr. Meador and to his coauthor, Dr. N. Browning, and from the U.K. Epilepsy Research Foundation to coauthor Dr. G. A. Baker.