Teenagers who are exposed to alcohol while in the womb exhibit altered brain connections consistent with impaired cognitive performance, according to a study.
Researchers have taken one of the first major steps in finding the biological changes in the brain that drive foetal alcohol spectrum disorder (FASD).
The study, published in the journal Chaos, analysed brain signals to find the long-term effects.
"This work presents major evidence that children exposed to alcohol prenatally are at risk of suffering from impaired cognitive abilities and other secondary factors," said Lin Gao from Xi'an Jiaotong University in China.
"Our study shows that there is no safe amount or safe stages during pregnancy for alcohol consumption," Gao said in a statement.
The researchers measured the responses from a brain imaging technique called magnetoencephalography (MEG).
FASD is one of the leading causes of intellectual disability worldwide and is linked to a wide array of neurological issues, including ADHD, researchers said.
While the prevailing theory links expectant mothers' alcohol consumption to cognitive impairments for children, questions about the extent of this effect remain, they said.
Despite the known link, researchers are uncertain about the precise mechanism by which alcohol alters the developing brain.
"The paper provides important integrative results for the field of FASD," said Julia Stephen from the Mind Research Network in US.
"These results may then indicate that simple sensory measures may provide sensitivity for brain deficits that affect the broader cognitive domain," Stephen said in a statement.
Previous attempts to study the brain circuitry in affected individuals have been hampered by the difficulty of drawing conclusions from complicated MEG data.
The researchers developed a sophisticated computer technique called Cortical Start Spatio-Temporal multidipole analysis that could identify which areas of the brain were active when research subjects were in the MEG machine.
After data from 19 FASD patients and 21 subjects without FASD was collected, the computational approach revealed several areas of the brain that showed impaired connectivity among the FASD group.
Subjects who were 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, researchers said.