Because breastfeeding has many psychological and medical benefits for both the mother and her child, many women would like to breastfeed.  However, all medications taken by the mother are secreted into the breast milk.  While various studies have addressed the safety of antiepileptic drugs (AEDs) in nursing infants, none have systematically assessed the long-term effects of exposure to these drugs on the cognitive development of children exposed to these agents through breastfeeding.  This is an especially important issue as it has been demonstrated that certain AEDs, most notably valproic acid, may negatively affect the developing brain, a process which occurs in utero and into the first few decades of the child’s life.

A recent study from Meador and colleagues was carried out as part of the Neurodevelopmental Effects of Antiepileptic Drugs Study, an ongoing prospective multicenter observational investigation designed to examine the long-term effects of in utero AED exposure on cognition. Pregnant women with epilepsy who were taking a single AED (carbamazepine, lamotrigine, phenytoin, or valproate) and were followed prospectively. In this report, the authors focus on the effects of breastfeeding during AED therapy on age 3 cognitive outcomes in 199 children at 3 years of age.

Outcomes were compared between children who were breastfed (n=199) and those who were not.  42% of children were breastfed. The median duration of breastfeeding was 6 months (range 3–24 months. IQs for breastfed children did not differ from non-breastfed children for all AEDs (combined and for each of the 4 individual AEDs). After adjusting for maternal IQ, mean adjusted IQ scores across all AEDs were 99 (range 96–103) for breastfed children and 98 (95–101) for non-breastfed children.

While these data are reassuring, there are several limitations to this study. First, the numbers of subjects included were not large enough to detect differences in outcomes among the different AEDs.  In addition, there are no control groups for comparison, such as women not taking AEDs or women taking AEDs only during breastfeeding and not during pregnancy.  In addition, IQ may be a relatively crude instrument for detecting subtle changes in cognitive development.  Despite these limitations, this study provides important information to women taking AEDs who are considering breastfeeding.

Ruta Nonacs, MD PhD

Meador KJ, Baker GA, Browning N, Clayton-Smith J, Combs-Cantrell DT, Cohen M, Kalayjian LA, Kanner A, Liporace JD, Pennell PB, Privitera M, Loring DW; NEAD Study Group. Effects of breastfeeding in children of women taking antiepileptic drugs. Neurology. 2010 Nov 30;75(22):1954-60. Epub 2010 Nov 24.