Abstracts

Rationale: Breastfeeding is known to have beneficial effects for both the mother and the child. However, there is concern that breastfeeding during antiepileptic drug (AED) therapy may be harmful to cognitive development. In a previous report (Meador et al., Neurology 2010), we noted no adverse effects on IQ at age 3 years from prior AEDs exposure via breastfeeding, but IQ at age 6 is more predictive of school performance and adult abilities. Here, we investigate the effects of prior AED exposure via breast milk on IQ at age 6 years in our cohort. Methods: The NEAD Study is a prospective observational multicenter study in the USA and UK, which enrolled pregnant women with epilepsy from 1999 to 2004, who were on AED monotherapy (i.e., carbamazepine, lamotrigine, phenytoin, or valproate). The investigation examined long-term neurodevelopmental effects of the children from these pregnancies. At age 6 years, 181 children were assessed using the Differential Abilities Scales (DAS) for whom we also had data on breastfeeding. Note that all mothers in this analysis continued taking AED after delivery. We also assessed other cognitive domains including: Verbal Index (word definition and similarities subtests of DAS, the Expressive One-Word Picture Vocabulary Test, and the phonological processing, comprehension of instructions and sentence repetition subtests of the NEPSY); Non-verbal Index (pattern construction, matrices, recall of designs subtests of DAS, and the arrows subtest of NEPSY, and the Developmental Test of Visual Motor Integration); Memory Index (Children s Memory Scale); Executive Index (verbal fluency, and visual attention subtests from the NEPSY). Results were analyzed as a function of whether the children had been breastfed or not. For our primary analysis, we employed a linear regression model with age 6 IQ as the dependent variable. Similar secondary analyses were done for the other cognitive measures.Results: Overall, 43% of the children were breastfed with an average duration of 6 months. There was no statistical difference (p=0.37) in breastfeeding rates across AED groups. Significant independent variables predicting age 6 IQ included maternal IQ (F=20.73, 1df, p<0.0001), AED group (F=9.08, 3df, p<0.0001), AED dose (F=6.43, 1df, p=0.012), periconceptional folate (F=10.82, 1df, p=0.001), and breastfeeding (F=5.98, 1df, p=0.016). IQ was higher overall by 4 points for children who were breastfed vs. those who were not breastfed (see Table 1 for results across AEDs). For the other cognitive domains, only Verbal Index differed across the breastfed and non-breastfed groups (p=0.03) with a higher score for breastfed children (see Table 2 for results across the cognitive domains).Conclusions: The results failed to show adverse effects of AED exposure via breast milk. Children who breastfed exhibited higher IQ and Verbal Index scores even though their mothers used AEDs. This is the only cohort in which the neurodevelopmental effects of breastfeeding while mothers took AEDs have been studied. However, caution is advised due to study limitations. Additional studies are needed.