According to a recent MRI study, drinking alcohol during pregnancy, even in low to moderate doses, can affect the baby’s brain structure and delay brain development. The study’s findings will be presented next week at the Radiological Society of North America’s annual meeting (RSNA).
Gregor Kasprian, M.D., associate professor of radiology at the Department of Biomedical Imaging and Image-guided Therapy of the Medical University of Vienna in Austria, and the study’s senior author said that “Fetal MRI is a highly specialized and safe examination method that allows us to make accurate statements about brain maturation prenatally”
Fetal alcohol spectrum disorders are a group of conditions that can affect the fetus if alcohol is consumed while pregnant. Babies born with fetal alcohol spectrum disorders may experience developmental delays in speech and language, learning impairments, or behavioral problems.
Lead author Patric Kienast, M.D., a Ph.D. student in the Department of Biomedical Imaging and Image-Guided Therapy, Division of Neuroradiology and Musculoskeletal Radiology at the Medical University of Vienna, said, “Unfortunately, many pregnant women are unaware of the influence of alcohol on the fetus during pregnancy”.
Researchers examined MRI scans of 24 fetuses who had prenatal alcohol exposure for the study. At the time of the MRI, the fetuses ranged in gestational age from 22 to 36 weeks. Anonymous surveys given to the mothers helped identify the mothers’ alcohol exposure. The Pregnancy Risk Assessment Monitoring System (PRAMS), a surveillance initiative of the Centers for Disease Control and Prevention and health departments, and the T-ACE Screening Tool, a measurement tool comprising four questions that detect risk drinking, were employed as questionnaires.
The right superior temporal sulcus (STS) was shallower and the fetus total maturation score (fTMS) was significantly lower in alcohol-exposed fetuses than in age-matched controls. Language perception, audiovisual integration, and social cognition are all involved in STS.
“We found the greatest changes in the temporal brain region and STS,” Dr. Kasprian said. “We know that this region, and specifically the formation of the STS, has a great influence on language development during childhood.”
Even at low alcohol exposure levels, the fetuses showed signs of brain changes.
“Seventeen of 24 mothers drank alcohol relatively infrequently, with average alcohol consumption of less than one alcoholic drink per week,” Dr. Kienast said. “Nevertheless, we were able to detect significant changes in these fetuses based on prenatal MRI.”
Two mothers drank four to six drinks a week, while three mothers consumed one to three. One mother had at least 14 drinks each week on average. Additionally, six mothers reported consuming at least one binge drinking incident (more than four drinks on one occasion) when they were pregnant.
According to the study’s authors, a delayed stage of myelination and less distinct gyrification in the frontal and occipital lobes could be directly responsible for a prenatal brain development delay.
According to the study’s authors, a delayed stage of myelination and less distinct gyrification in the frontal and occipital lobes could be directly responsible for a prenatal brain development delay.
The function of the nervous system and the brain relies on the myelination process. Nerve cells are protected by myelin, which speeds up information transmission. Myelination has a direct role in crucial newborn developmental milestones like rolling over, crawling, and language development.
The term “gyrification” describes how the cerebral cortex develops its folds. With less room in the skull, this folding increases the cortex’s surface area, enhancing cognitive function. Functionality is reduced when gyrification is minimized.
“Pregnant women should strictly avoid alcohol consumption,” Dr. Kienast said. “As we show in our study, even low levels of alcohol consumption can lead to structural changes in brain development and delayed brain maturation.”
It is unknown how these anatomical alterations may impact the postnatal brain development of these infants.
“To assess this accurately, we need to wait for the children who were examined as fetuses at that time to get a little older, so that we can invite them back for further examinations,” Dr. Kienast said. “However, we can strongly assume that the changes we discovered contribute to the cognitive and behavioral difficulties that may occur during childhood.”
