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Developmental Biology - Alcohol in Pregnancy

No Safe Amount of Alcohol During Pregnancy

Brain connectivity issues found in children who experience prenatal alcohol exposure...

An international group of researchers has taken one of the first major steps in finding the biological changes in the brain that drive fetal alcohol spectrum disorder (FASD). New work using chaos theory to analyze brain signals, discussed in the journal Chaos, from AIP Publishing, shows the long-term effects.

Researchers found that teenagers exposed to alcohol while in the womb showed altered brain connections consistent with impaired cognitive performance. Their findings were reached by measuring the responses from a brain imaging technique called magnetoencephalography (MEG) and then analyzing them with tools developed using chaos theory.
FASD is one of the leading causes of intellectual disability worldwide and linked to a wide array of neurological issues, including ADHD.

While the prevailing theory links expectant mothers' alcohol consumption to cognitive impairments in their children, questions about the extent of this effect remain. Despite this known link, researchers are uncertain about the precise mechanism by which alcohol alters the developing brain. The group's efforts mark one of the first times researchers have been able to quantify the effects of alcohol exposure on the developing brain.

"The paper provides important integrative results for the field of FASD. These results may then indicate that simple sensory measures may provide sensitivity for brain deficits that affect the broader cognitive domain," explains Julia Stephen, professor of Translational Neuroscience & Director at the Mind Research Network, and an author on the paper. Previous attempts to study the brain circuitry in affected individuals have been hampered by the difficulty of drawing conclusions from complicated MEG data.
To uncover the root of the problem, team members developed a computer technique called Cortical Start Spatio-Temporal multidipole analysis, in order to identify areas of the brain made active when research subjects underwent MEG evaluation.

After collecting data from 19 FASD patients and 21 subjects without FASD, among the FASD group the computational approach revealed several areas of the brain with impaired connectivity.
Subjects exposed to alcohol in the womb were more likely to have issues with connections through their corpus callosum, the band of brain tissue that connects the left and right halves of the brain. Deficits in this area have been reported in people with schizophrenia, multiple sclerosis, autism, depression and abnormalities in sensation.

"This work presents major evidence that children exposed to alcohol prenatally are at risk of suffering from impaired cognitive abilities and other secondary factors," says Lin Gao, of the State Key Laboratory of Manufacturing Systems Engineering, Xi’an Jiaotong University and Key Laboratory of Complex System Control and Intelligent Information Processing, Xi’an University of Technology, Shaanxi, People’s Republic of China; and author on the paper. "Our study ... shows that there is no safe amount or safe stages during pregnancy for alcohol consumption."

It is common knowledge that alcohol consumption during pregnancy would cause cognitive impairment in children. However, recent works suggested that the risk of drinking during pregnancy may have been exaggerated. It is critical to determine whether and up to which amount the consumption of alcohol will affect the cognitive development of children. We evaluate time-varying functional connectivity using magnetoencephalogram data from somatosensory evoked response experiments for 19 teenage subjects with prenatal alcohol exposure and 21 healthy control teenage subjects using a new time-varying connectivity approach, combining renormalised partial directed coherence with state space modeling. Children exposed to alcohol prenatally are at risk of developing a Fetal Alcohol Spectrum Disorder (FASD) characterized by cerebral connectivity deficiency and impaired cognitive abilities. Through a comparison study of teenage subjects exposed to alcohol prenatally with healthy control subjects, we establish that the inter-hemispheric connectivity is deficient for the former, which may lead to disruption in the cortical inter-hemispheric connectivity and deficits in higher order cognitive functions as measured by an IQ test, for example. We provide quantitative evidence that the disruption is correlated with cognitive deficits. These findings could lead to a novel, highly sensitive biomarker for FASD and support a recommendation of no safe amount of alcohol consumption during pregnancy.

Fetal alcohol spectrum disorders (FASDs), characterised by impaired cognitive abilities, are a group of conditions that can occur in a person whose mother has consumed alcohol during pregnancy. Surveys from the United States have found that about 10% of pregnant women have consumed alcohol in the last month and 20% to 30% at some point during the course of the pregnancy. Although there is clear evidence that children exposed to alcohol prenatally are at risk of developing an FASD, some studies have argued that the risk of problems depends on the amount consumed, the frequency of consumption, or when during pregnancy the alcohol was consumed. Our study involving experimental data collected from teenage subjects, combined with mathematical modeling, shows that there is no safe amount or safe stages during pregnancy for alcohol consumption. We employ a new time-varying connectivity approach to estimate the fast changing information flow among the brain sources using magnetoencephalogram data of somatosensory evoked response experiments from 19 teenage subjects with prenatal alcohol exposure (PAE) and 21 healthy control (HC) teenage subjects. We demonstrate that the inter-hemispheric connectivity is deficient for subjects with prenatal alcohol exposure. A lack of the inter-hemispheric connectivity is known to facilitate autism, stroke, schizophrenia, as well as dementia, disrupts the cognitive performance, and may lead to neurobehavioral deficits. We show that the disruption in the inter-hemispheric connectivity observed in this study is correlated with cognitive deficits associated with FASD, suggesting a potential new biomarker for FASD. Based on our findings, we support the recommendation of no safe amount of alcohol during pregnancy.

Lin Gao, Celso Grebogi, Ying-Cheng Lai, Julia Stephen, Tongsheng Zhang, Yuanli Li, Hai Peng Ren, Dichen Li, Jue Wang, Bjoern Schelter and Linda Sommerlade.

The study was supported by the National Institute of General Medical Sciences and the National Cancer Institute of the National Institutes of Health (P50GM107618 and U54CA225088). DOI: 10.1016/j.cels.2019.03.006.

About The Journal Chaos
Chaos is devoted to increasing the understanding of nonlinear phenomena in all disciplines and describing their manifestations in a manner comprehensible to researchers from a broad spectrum of disciplines. See http://chaos.aip.org.

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Apr 29 2019   Fetal Timeline   Maternal Timeline   News  

Reconstructed networks of primary (RED DOTS) and secondary (GREEN-BLUE DOTS)
somatosensory cortex reflect a lack of inter-hemishperic connectivity (201 to 420 miliseconds)
after stimulus in the late response of children prenatlly exposed to alcohol.
CREDIT: Gao Lin and Linda Sommerlade.

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