Evaluation of Brain Alterations and Behavior in Children With Low Levels of Prenatal Alcohol Exposure
Abstract
Importance
High levels of prenatal alcohol exposure (PAE) are associated with widespread behavioral and cognitive problems as well as structural alterations of the brain. However, it remains unclear whether low levels of PAE affect brain structure and function, and prior studies generally have not had well-matched control populations (eg, for sociodemographic variables).
Objective
To compare structural brain alterations and behavioral changes in children with lower levels of prenatal alcohol exposure with those of well-matched controls with no prenatal alcohol exposure.
Design, Setting, and Participants
In this cross-sectional study, participants were selected from the Adolescent Brain Cognitive Development study. Children with prenatal alcohol exposure were compared with controls matched for age, sex, family income, maternal educational level, and caregiver status. Neither group had prenatal exposure to other adverse substances (eg, tobacco, cannabis, illicit drugs).
Data were collected from September 1, 2016, to November 15, 2018, and analyzed from October 14, 2020, to February 14, 2022.
Exposures
Diffusion tensor imaging, resting-state functional magnetic resonance imaging (MRI), and Child Behavior Checklist (CBCL) administration.
Main Outcomes and Measures
Fractional anisotropy (FA); mean, axial, and radial diffusivity from diffusion tensor imaging; brain functional signal variations from functional MRI; and several scores, including internalizing and externalizing behavior problems, from the CBCL.
Spearman correlation coefficients between diffusion tensor imaging and functional MRI measures and the CBCL scores were calculated.
Results
A total of 270 children were included in the analysis, consisting of 135 children with prenatal alcohol exposure and 135 unexposed controls.
Children with prenatal alcohol exposure had lower mean (SD) FA in white matter of the left postcentral, left inferior parietal, left planum temporale, left inferior occipital, and right middle occipital areas compared with controls, and higher fractional anisotropy in the gray matter of the putamen.
Externalizing behavior scores were higher (worse) in children with PAE than in controls.
Several of these regions had significant group-behavior interactions, such that the higher fractional anisotropy was associated with less problematic behaviors in controls but no associations were present in the prenatal alcohol exposure group.
Conclusions and Relevance
In this cross-sectional study, children with low levels of prenatal alcohol exposure had lower fractional anisotropy and more behavioral problems compared with a well-matched control group.
These results suggest that prenatal alcohol exposure, even in small amounts, has a measurable effect on brain structure in children.
Research interpretation
The researchers in this study answer the question “how do brain structure and behavior of children with low levels of prenatal alcohol exposure (PAE) differ compared with those of a well-matched control group of children?”
The study examined 135 children with low levels of PAE and 135 unexposed control group of children. The average age of the children were about 9 years.
The researchers found that, children with PAE had lower fractional anisotropy in several white matter areas of the brain compared with children in the control group. Fractional anisotropy is a measure of connectivity in the brain.
The result means that connectivity in the brain had reduced among children who were exposed to alcohol prenatally.
Higher fractional anisotropy or better brain connectivity was associated with less problematic behaviors among the children in the control group who were not exposed to alcohol prenatally. No such assoiciation was found for children with PAE.
The children with PAE also had worse externalizing behavior scores than the control group. According to Springer, externalizing behavior comprises any of a wide variety of generally antisocial acts (i.e., acts that violate social norms and/or are harmful to others). These acts include those that are targeted at another individual (e.g., aggression), as well as acts that may be considered victimless (e.g., substance use).
These findings suggest that even small amounts of PAE are associated with structural brain alterations, highlighting the importance of evidence-based policy making and underscoring the need to consider prenatal exposures in future studies of pediatric brain development.
