Relationship of child IQ to parental IQ and education in children with fetal antiepileptic drug exposure.
Clinical trial designs need to control for genetic and environmental influences when examining cognitive outcomes in children for whom clinical considerations preclude randomization. However, the contributions of maternal and paternal IQ and education to pediatric cognitive outcomes are uncertain in disease populations. The Neurodevelopmental Effects of Antiepileptic Drugs (NEAD) Study is an ongoing prospective observational multicenter study in the United States and United Kingdom, which enrolled pregnant women with epilepsy to determine if differential long-term neurodevelopmental effects exist across four commonly used antiepileptic drugs. Here, we examined the relationship of IQ and education in both parents to child IQ at age 3 years. IQ and education for both parents were statistically correlated to child IQ. However, paternal IQ and education were not significant after accounting for maternal IQ effects. Because maternal IQ and education are independently related to child cognitive outcome, both should be assessed in studies investigating the effects of fetal drug exposures or other environmental factors that could affect the child's cognitive outcome.