Advice for pregnant patients with epilepsy
Dr. Meador explained that risk for adverse effects with antiseizure medication always needs to be balanced with risk for seizures if the medication was not used.
“In women planning a pregnancy, we recommend that they plan ahead with their physician to try and use the safest antiseizure medication and gain good control beforehand and then maintain the same blood levels of whichever drug is being used during pregnancy,” Dr. Meador said. “At present, lamotrigine and levetiracetam are the two safest drugs to use in pregnancy. They both look generally very safe compared with some other epilepsy drugs – such as valproate, which poses a serious risk to cognitive and behavioral development.”
He also advised that women should be taking folic acid regularly, as this has been shown to be related to improved cognitive and behavioral outcomes. “Since half of pregnancies are not planned, it is important to take these actions before pregnancy,” he added.
The current study involved 289 women with epilepsy and 89 women without epilepsy, all of whom enrolled in the study during pregnancy. Use of antiseizure medications was recorded. Of the women with epilepsy, 74% were on monotherapy, with 43% on lamotrigine and 37% on levetiracetam. There were 4% who took no drug and 22% took more than one drug. Of those who took more than one drug, close to half took a combination of lamotrigine and levetiracetam. Levels of medications in the blood of the women with epilepsy were measured in the third trimester.
Assessment of neurobehavioral development
For the current analysis, the children were evaluated at age 3 with a series of cognitive and developmental tests that measured vocabulary, listening comprehension, number recall, and pattern recognition, and results were adjusted for mother’s IQ, education level, age at enrollment, postbirth average BAI (Beck Anxiety Inventory score), and child’s ethnicity, sex, and breastfeeding status.
The primary outcome showed that verbal Index scores at age 3 did not differ for children of women with epilepsy versus those for children of women without epilepsy (LS mean 102.7 vs. 102.1).
Antiseizure medication exposure as evident by the maximum third trimester blood levels was not related to verbal index scores (n = 265; adjusted parameter estimate, -1.9; 95% confidence interval, -6.8 to 3.1).
General conceptual ability scores also did not differ between the two groups: 105.1 for children of women with epilepsy versus 103.5 for children of healthy women.
In terms of exposure levels, the third trimester maximum observed ratio of antiseizure medication blood levels was not significantly associated with adjusted general conceptual ability scores for children of women with epilepsy; neither were monotherapies or polytherapies evaluated separately, Dr. Meador reported.
However, when the verbal index scores for the main antiepileptic drug groups were analyzed separately, exposure level to levetiracetam was the only one that was significant, with a P value of .028. But Dr. Meador again stressed that this finding should be interpreted with caution given that it is a secondary exploratory analysis without control for multiple comparisons.
The researchers plan to assess these children at older ages where evaluations are more sensitive to ultimate outcomes.
“Information on use in pregnancy for most antiseizure medications is still unknown, so further studies to assess risks for the newer antiseizure medications are needed,” Dr. Meador added. “Further, additional research is needed on the underlying mechanisms including genetic predispositions, since teratogens act on a susceptible genotype.”
The study was supported by the National Institutes of Health, the National Institute of Neurological Disorders and Stroke, and the Eunice Kennedy Shriver National Institute of Child Health and Human Development.
A version of this article first appeared on Medscape.com.