Date of Award


Document Type

Open Access Thesis

Degree Name

Master of Science (MS)


Developmental and Brain Sciences

First Advisor

Jane Adams

Second Advisor

Vivian Ciaramitaro

Third Advisor

Richard Hunter


Phenobarbital is one of the oldest medications used for the treatment of epilepsy. Although its use has declined in many developed nations, phenobarbital is still a first-line treatment in several developing countries across the globe. If possible, current American Academy of Neurology guidelines advise against the use of phenobarbital during pregnancy due to an increased risk for structural malformations. However, less is known about the risk that prenatal exposure to phenobarbital poses to the cognitive and behavioral development of the child. Adams et al (in progress) have shown that, in comparison to demographically matched controls, children prenatally exposed to phenobarbital for the treatment of maternal epilepsy have a significant reduction in general mental ability and verbal intelligence. In this paper, we aim to further explore the impact of prenatal exposure to phenobarbital on verbal abilities by examining performance on individual verbal subtests within the original testing battery. The performance of children that were prenatally-exposed to phenobarbital and demographically matched controls was compared on a selection of verbal subtests from the Wechsler Intelligence Scale for Children, 3rd Edition (WISC-III ), the Stanford-Binet Intelligence Scales, 4th Edition (SB-IV), and the Wechsler Memory Scale, Revised (WMS-R). Maternal intelligence was assessed with the Wechsler Abbreviated Intelligence Scale, Revised (WAIS-R). Initial analyses were conducted to explore the effects of sex and treatment on verbal performance. However, no significant effects of sex nor any interaction effects were found, so sex was removed from later analyses. ANCOVA controlling for maternal intelligence confirmed a significant reduction in general mental ability and verbal intelligence in the sample of children prenatally exposed to phenobarbital. Multivariate ANCOVA controlling for maternal intelligence revealed a significant effect of exposure group on verbal performance across measures. Follow-up analyses revealed that children prenatally exposed to phenobarbital performed significantly worse than controls on the Vocabulary and Arithmetic subtests from the WISC-III and on a test of Story Memory from the WMS-R. Combined with previous findings by Adams et al., the results of this study further support an effect of prenatal exposure to phenobarbital on children’s verbal abilities.