Does breastfeeding in mothers who take antiepileptic drugs (AEDs) affect cognitive outcomes in their children?
Not according to a new analysis by investigators who reported their findings at the American Epilepsy Society annual meeting last month. The investigators found that the children who had been breastfed by women taking AEDs did not have worse cognitive outcomes at 6 years of age.
The study — which used data collected from the NEAD (Neurodevelopmental Effects of Antiepileptic Drugs) study, an observational, multicenter study in the US and UK — found that the children who were breastfed actually had higher IQ scores and higher verbal index scores at age 6 than those who were not breastfed.
The study was a follow-up on the cognitive outcomes of children whose mothers had taken carbamazepine, lamotrigine, phenytoin, or valproate while they were pregnant. It’s the only cohort in which breastfed children of mothers on AEDs have been compared with the children of mothers who did not take AEDs while breastfeeding.
Despite the well-known benefits of breastfeeding on the development of children, there is still some consternation about women breastfeeding while they’re taking AEDs, said study author Kimford Meador, MD, professor of neurology at Stanford University, who was at Emory at the time of the study.
“I have women all the time coming into the clinic stating a doctor or nurse told them, ‘Never breastfeed,’ a conclusion based solely on a theoretical risk without any data,” Dr. Meador said. “But the data doesn’t seem to support that concern.”
The researchers previously showed that there were no adverse effects on IQ at age 3 years from breastfeeding while mothers were taking AEDs. But IQ at age 6 is more predictive of how children will perform in school and of their intelligence as adults.
And at age 6, the overall IQ for the children who were breastfed was 108, while the IQ for those who weren’t breastfed was 104. Those are figures after adjustment for the IQ of the mother, AED group, AED dose, and preconceptual folate level.
As seen in previous studies, the IQs for the children of mothers who were taking valproate the lowest among the four drugs, with an IQ at age 6 of 105 for those who were breastfed and 94 for those who were not breastfed.
Dr. Meador said the results should be reason for doctors to encourage women on AEDs to breastfeed their children if they want to, since there seems to be nothing adverse about doing so.
“Even if you don’t think that the positive IQ effect here is real, there’s certainly no indication of a negative cognitive effect, and there are other known positive effects of breastfeeding,” he said. “That’s why I think if women want to breastfeed, I think it’s fine. That’s the general take-home message for women that I follow.”
He stressed that the findings only apply to women who have already been on AEDs while pregnant, and not the unusual cases of women who might have had to start taking AEDs after delivering a baby.
Dr. Meador said that one explanation of the findings is that perhaps it’s the peak dose that matters, and not the duration of the exposure, as has been found in animal studies.
“The peak levels are going to be much less in the children being breastfed than they’re going to be in children in the womb — the level’s going to be the same in the womb as it is for the mother,” he said. But in breastfed children, “how much is secreted in the milk? How much do they take in? How fast does the child metabolize the drug? All these other factors come into play.”
It might be a matter of, “If they’re going to have a problem, they’ve already taken the hit in utero,” he said.
It’s better to “take the known benefit rather than the theoretical risk,” he added.
He acknowledged that the “quantification of breastfeeding is not as good as I would like and we did not measure AED levels in the child.” He is leading an ongoing new study with women on AEDs in which the exposure will be quantified, and the level of the drugs in the children’s blood will be measured.
Read the full discussion on these findings in the Dec. 19 issue of Neurology Today. See our collection of stories on epilepsy and pregnancy: http://bit.ly/1cFyZbh.