Drinking alcohol during pregnancy can change the baby's brain structure

Drinking alcohol during pregnancy can change the baby's brain structure

A new MRI study has shown that consuming alcohol during pregnancy, even in small to moderate amounts, can change the baby's brain structure and delay brain development. The results of the study will be presented next week at the annual meeting of the Radiological Society of North America (RSNA).

Fetal MRI is a highly specialized and safe examination method that allows us to make precise statements about brain maturation prenatally.”

Gregor Kasprian, MD, lead author of the study, associate professor of radiology, Department of Biomedical Imaging and Image-Guided Therapy at the Medical University of Vienna in Austria

Drinking alcohol during pregnancy can expose the fetus to a group of conditions called fetal alcohol spectrum disorders. Babies born with fetal alcohol spectrum disorders may develop learning difficulties, behavior problems, or speech and language delays.

"Unfortunately, many pregnant women are unaware of the impact of alcohol on the fetus during pregnancy," said lead author Patric Kienast, M.D., a Ph.D. Student in the Department of Biomedical Imaging and Image-Guided Therapy, Clinical Department of Neuroradiology and Musculoskeletal Radiology at the Medical University of Vienna. “Therefore, it is our responsibility not only to conduct research but also to actively educate the public about the effects of alcohol on the fetus.”

For the study, researchers analyzed MRI scans of 24 fetuses with prenatal alcohol exposure. The fetuses were between 22 and 36 weeks of gestation at the time of MRI. Alcohol exposure was determined through anonymous surveys of the mothers. The questionnaires used were the Pregnancy Risk Assessment Monitoring System (PRAMS), a surveillance project of the Centers for Disease Control and Prevention and health departments, and the T-ACE Screening Tool, a measurement tool with four questions that identify risky drinking.

In alcohol-exposed fetuses, the total fetal maturation score (fTMS) was significantly lower than in age-matched controls, and the right superior temporal sulcus (STS) was flatter. The STS deals with social cognition, audiovisual integration and speech perception.

“We found the largest changes in the temporal region of the brain and in the STS,” said Dr. Casprian. “We know that this region and in particular the education of the STS has a major influence on language development in children.”

Brain changes were observed in the fetuses even with low levels of alcohol exposure.

"Seventeen of 24 mothers drank alcohol relatively infrequently, with average alcohol consumption being less than one alcoholic drink per week," said Dr. Kienast. “Nevertheless, we were able to detect significant changes in these fetuses using prenatal MRI.”

Three mothers drank one to three drinks per week and two mothers drank four to six drinks per week. On average, a mother consumed 14 or more drinks per week. Six mothers also reported at least one binge drink (more than four drinks on one occasion) during pregnancy.

According to the researchers, delayed fetal brain development may be specifically related to a delayed stage of myelination and less pronounced gyrification in the frontal and occipital lobes.

The myelination process is crucial for the functioning of the brain and nervous system. Myelin protects nerve cells and allows them to transmit information more quickly. Important developmental milestones in infants as rolling over, crawling and language processing are directly linked to myelination.

Gyrification refers to the formation of the folds of the cerebral cortex. This folding increases the surface area of ​​the cerebral cortex within limited space in the skull and thus enables an increase in cognitive performance. When gyrification is reduced, functionality is reduced.

“Pregnant women should strictly avoid alcohol consumption,” says Dr. Kienast. “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 unclear how these structural changes will affect these babies' brain development after birth.

“In order to be able to assess this accurately, we have to wait until the children who were examined as fetuses get a little older so that we can invite them back for further examinations,” says Dr. Kienast. “However, we have strong confidence that the changes we discovered contribute to the cognitive and behavioral difficulties that can occur during childhood.”

Co-authors are Marlene Stümpflen, MD, Daniela Prayer, MD, Benjamin Sigl, MD, Mariana Schuette, MD, Ph.D., and Sarah Glatter, MD, MMSc.

Source:

Radiological Society of North America

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