An international team of researchers takes a major step in finding biological changes in the brain driving fetal alcohol spectrum disorder (FASD). New work that applies advanced mathematical modeling to brain activity offers new insight into how prenatal alcohol exposure disrupts neural connectivity and long-term cognitive function.
Study Findings
Researchers discovered that teenagers who had been exposed to alcohol while still inside the womb had significantly weakened inter-hemispheric connectivity—particularly between areas of the somatosensory cortex—linked to lower IQ and impaired executive functioning. The findings were based on measuring responses from a brain imaging technique known as magnetoencephalography (MEG). Researchers then analyzed the responses using a technique called renormalized partial directed coherence (rPDC), which allowed them to track how information flowed between brain regions over time.
FASD is among the leading causes of intellectual disability in the world. It is also linked to a wide range of neurological issues that include ADHD. The theory links the alcohol consumption of expectant mothers to cognitive impairment in children. However, questions exist about the extent of this effect. Researchers are still uncertain about the particular mechanism by which alcohol affects developing brains.
This was one of the first studies to quantitatively link prenatal alcohol exposure to measurable deficits in brain connectivity using MEG-based real-time analysis.
Expert Insight from Co-Author Dr. Julia Stephen
Dr. Julia Stephen, a co-author of the study and a professor of translational neuroscience at the Mind Research Network, noted that the findings offer integrative insights into FASD-related brain deficits. She said that the results could be an indication that simple sensory measures could provide sensitivity for brain deficits. In this case, the “sensory measure” referred to somatosensory evoked responses—how the brain reacts to small puffs of air on a subject’s finger.
Earlier attempts to study the brain’s circuitry in affected individuals were hampered by difficulties in drawing conclusions arising from the complicated MEG data.
To understand the root of that problem, the team came up with a computer technique known as Cortical Start Spatio-Temporal multi-dipole analysis. The technique could be used to identify the active brain areas once research subjects got into the MEG machine.
Data from 21 subjects who did not have FASD and 19 patients with FASD were collected. The study found that the most significant deficits were in late-stage inter-hemispheric connectivity between secondary somatosensory regions (SII-l and SII-r), which play a critical role in integrating sensory input and coordinating higher-level cognition.
The subjects who had been exposed to alcohol while still in the womb had a higher chance of having connection issues through the corpus callosum. This is the band of brain tissue that connects the right and the left sides of the brain. Deficits in this area have been found in people with:
- Autism
- Schizophrenia
- Depression
- Multiple sclerosis
- Abnormalities in sensation
FAQs
What is FASD?
Fetal Alcohol Spectrum Disorder—a range of cognitive and behavioral issues caused by alcohol exposure during pregnancy.
What is inter-hemispheric connectivity?
The brain’s ability to share information between its left and right sides.
What is MEG?
Magnetoencephalography—a brain scan that tracks electrical activity in real time.
What is rPDC?
Renormalized Partial Directed Coherence—a method to measure how brain regions communicate.
What did the study show?
Alcohol exposure in the womb weakens brain connectivity, which is linked to lower IQ and poor decision-making.
Does occasional drinking matter?
Yes. Even occasional alcohol use during pregnancy was tied to brain changes and cognitive decline.
Can FASD be diagnosed early?
Possibly. This study points to a brain scan marker that could help detect FASD before symptoms fully appear.
Is any amount of alcohol safe during pregnancy?
No. The study supports total abstinence—there’s no proven safe amount or stage.
Related Reading:
Is the Cure for Alcoholism Hidden in Our Brains? New Boston University Study Sheds Light
Do You Want to Avoid Dementia? Why Quitting Alcohol After 65 – Or Even Sooner – Might Be Key
Final Thoughts
Lin Gao said that the researchers’ work presented major evidence that children who had been exposed to alcohol before birth were at risk of acquiring impaired cognitive abilities, plus other secondary factors.
Notably, both occasional and consistent drinking during pregnancy were associated with connectivity loss and cognitive decline—indicating there is no “safe” pattern of alcohol consumption. The study also found a strong statistical correlation between the level of brain disruption and lower IQ scores and poorer performance on executive function tests.
There is no safe stage to consume alcohol or a safe amount of alcohol to consume during pregnancy. For women who are pregnant or trying to conceive, this study reinforces the importance of avoiding alcohol entirely, no matter the amount or timing. If you’re unsure or need support, speak to a healthcare provider; early guidance can make a big difference.
The authors hope that their work will inspire other researchers to perform similar research on diseases such as FASD.
These findings not only strengthen the case for total abstinence during pregnancy but also offer a potential biomarker to diagnose FASD earlier through noninvasive brain imaging.
References
Gao, L., Grebogi, C., Lai, Y-C., Stephen, J., Zhang, T., Li, Y., Ren, H., Li, D., Wang, J., Schelter, B., & Sommerlade, L. (2019). Quantitative assessment of cerebral connectivity deficiency and cognitive impairment in children with prenatal alcohol exposure. Chaos, 29(4), 041101. https://doi.org/10.1063/1.5089527
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