Heavy Prenatal Alcohol Exposure is Related to Smaller Corpus Callosum in Newborn MRI Scans

Abstract

Background MRI studies have consistently demonstrated disproportionately smaller corpus callosa in individuals with a history of prenatal alcohol exposure but have not previously examined the feasibility of detecting this effect in infants. Tissue segmentation of the newborn brain is challenging because analysis techniques developed for the adult brain are not directly transferable, and segmentation for cerebral morphometry is difficult in neonates, due to the latter’s incomplete myelination. This study is the first to use volumetric structural MRI to investigate prenatal alcohol exposure effects in newborns using manual tracing and to examine the cross-sectional area of the corpus callosum (CC). Methods 43 nonsedated infants born to 32 Cape Coloured heavy drinkers and 11 controls recruited prospectively during pregnancy were scanned using a custom-designed birdcage coil for infants, which increases signal-to-noise ratio almost two-fold compared to the standard head coil. Alcohol use was ascertained prospectively during pregnancy, and FASD diagnosis was conducted by expert dysmorphologists. Data were acquired using a multi-echo FLASH protocol adapted for newborns, and a knowledge-based procedure was used to hand-segment the neonatal brains. Results CC was disproportionately smaller in alcohol-exposed neonates than controls after controlling for intracranial volume. By contrast, CC area was unrelated to infant sex, gestational age, age at scan, or maternal smoking, marijuana, or methamphetamine use during pregnancy. Conclusions Given that midline craniofacial anomalies have been recognized as a hallmark of FAS in humans and animal models since this syndrome was first identified, the CC deficit identified here in newborns may support early identification of a range of midline structural impairments. Smaller CC during the newborn period may provide an early indicator of fetal alcohol-related cognitive deficits that have been linked to this critically important brain structure in childhood and adolescence.

Prenatal exposures and infant brain: Review of magnetic resonance imaging studies and a population description analysis

“…The findings of lower total GM volume are consistent with results on older children, which suggests that they are pervasive (Archibald et al, 2001;Nardelli, Lebel, Rasmussen, Andrew, & Beaulieu, 2011). Structurally, PAE has also been linked to decreased corpus callosum area (Jacobson et al, 2017). Diffusion tensor imaging (DTI) studies on the topic have found lowered axial diffusivity (AD) values in PAE infants (Donald, Roos, et al, 2015;Taylor et al, 2015).…”

“…A 2016 study by found that PAE was associated with reduced overall GM volumes, most notably in bilateral amygdalae, left hippocampus, and left thalamus at 3 weeks of age and with slightly delayed socio-emotional development compared with control infants at 6 months of age. Structurally, PAE has also been linked to decreased corpus callosum area (Jacobson et al, 2017). Structurally, PAE has also been linked to decreased corpus callosum area (Jacobson et al, 2017).…”

Multivariate models of brain volume for identification of children and adolescents with fetal alcohol spectrum disorder

“…Some structures may be disproportionately affected in FASD with larger proportional reductions in specific deep gray matter structures such as the caudate and putamen (Nardelli, Lebel, Rasmussen, Andrew, & Beaulieu, 2011;Roussotte et al, 2012). These brain volume reductions have also been reported in infants and neonates with PAE for the corpus callosum (Jacobson et al, 2017) and gray matter (Donald et al, 2016). In addition, larger volume reductions have been observed in males with FASD suggesting sex differences (Chen, Coles, Lynch, & Hu, 2012;Dudek, Skocic, Sheard, & Rovet, 2014;Treit et al, 2017).…”

The Unifying Effects of Maternal-Placental-Fetal Axis Dysregulation on Neurodevelopment Following Infectious and Toxic In Utero Insults

“…Significantly, the corpus callosum, a major white matter structure essential for interhemispheric communication, has been reported to be disproportionately smaller in alcoholexposed neonates (195,199,200,(204)(205)(206). Structural deficits in the corpus callosum may lead to poor cognitive performance, and impaired sensory, motor and higher-order neural communication (204)(205)(206), as a result of poor connectivity, dysregulated interhemispheric integration, and impaired processing. Likewise, diffusion imaging studies link abnormal callosal microstructure and structural coherence with impaired myelination, diffuse fiber bundles and poor axonal integrity (204,207).…”

“…Structural deficits in the corpus callosum may lead to poor cognitive performance, and impaired sensory, motor and higher-order neural communication (204)(205)(206), as a result of poor connectivity, dysregulated interhemispheric integration, and impaired processing. Likewise, diffusion imaging studies link abnormal callosal microstructure and structural coherence with impaired myelination, diffuse fiber bundles and poor axonal integrity (204,207). Significantly, these neuroimaging studies corroborate the first autopsy studies of FAS, including those revealing impaired cell migration, and agenesis or thinning of the corpus callosum (183,208).…”