Drinking during pregnancy changes the structure of an unborn baby’s brain


CHICAGO, Illinois – Drinking during pregnancy is a combination that doctors tell women to avoid at all costs. Today, a new study reveals that alcohol can alter the structure of an unborn baby’s brain.

A team from the Radiological Society of North America claims that alcohol consumption can lead to fetal alcohol syndrome (FAS), a series of developmental problems caused by exposure to alcohol in the womb. The results come from an analysis of 500 expectant mothers in Austria undergoing MRI scans for clinical reasons.

“Fetal alcohol syndrome is a global problem in countries where alcohol is freely available,” says lead author Professor Gregor Kasprian of the Vienna Medical University in a press release. “An estimated 9.8% of all pregnant women drink alcohol during pregnancy, and that number is probably underestimated.”

The team found significant brain changes in fetuses exposed to alcohol compared to healthy babies whose mothers avoided drinking.

“It appears that exposure to alcohol during pregnancy puts the brain on a developmental path that deviates from a normal trajectory,” continues Professor Kasprian. “Fetal MRI is a very powerful tool for characterizing brain development not only under genetic conditions, but also under acquired conditions resulting from exposure to toxic agents.”

How Does Alcohol Affect a Baby’s Brain?

In particular, the volume in two regions of the brain – the collosum body and the periventricular zone – increased or decreased with alcohol consumption. The first is a large bundle of over 200 million nerve fibers that communicate between the right and left sides of the brain. The latter is found at the base of the brain and is the “factory” of the organ’s neurons.

“One of the main features of our study is that we looked at many smaller sub-compartments of the brain,” says co-author Dr. Marlene Stuempflen.

FAS is the most serious form of a group of conditions that doctors call Fetal Alcohol Spectrum Disorder.

Super-resolution MRI reconstruction and atlas-based tissue segmentation. (A, B) Post-processed MRI super-resolution reconstructions in the axial and sagittal planes of a fetus at 26 + 6 GW. (C, D) Tissue segmentation based on the respective manually corrected atlas. Color coding: blue – external CSF spaces, red – cortex, orange – subcortical parenchyma, brown – periventricular zone, dark green – ganglionic eminence, white – ventricular system, dark blue – corpus callosum, yellow ?? nuclei dark gray (basal ganglia and thalamus), light green – brainstem, light blue – cerebellum, turquoise – left hippocampus, gray – right hippocampus.

Babies can have specific physical characteristics such as small eyes, a thin upper lip, and a smooth area under the nose. Other problems include mental deficits, malformations of bones and major organs, inhibited growth, and diseases of the central nervous system.

Children with FAS may also suffer from poor motor skills, higher death rates, and difficulties with learning, memory, social interaction, and attention span. One in 70 pregnancies with alcohol exposure results in FAS, according to Professor Kasprian.

Mapping alcohol damage to the brain

In the first such study, 51 participants admitted to consuming alcohol during their pregnancy. They participated in a surveillance project called PRAMS (Pregnancy Risk Assessment Monitoring System) and completed another questionnaire called T-ACE which tracks risky drinking behaviors.

“We provided a safe environment where women could feel comfortable answering questions honestly,” says Prof Kasprian.

The researchers combined statistical analysis with super-resolution imaging that created a data set to reconstruct each fetal brain. They completed 12 different brain structures, calculating the total and segmented volumes of specific compartments.

“This is the first time that a prenatal imaging study has been able to quantify these early changes associated with alcohol,” adds Dr Stuempflen.

No safe amount during pregnancy

The collosum body is the primary connection between the left and right sides of the brain. Dr Stuempflen notes that it is normal for this very central structure to be affected by alcohol consumption, as the clinical symptoms of FAS disorders are very diverse. They cannot be located in a specific substructure of the brain.

“The changes observed in the periventricular zone, where all neurons originate, also reflect an overall effect on the development and function of the brain,” reports Dr Stuempflen.

The identification of a thicker collosum body in alcohol-positive fetuses was surprising, as it is thinner in infants with FAS disorders.

“There are many postnatal studies on infants exposed to alcohol,” notes Dr. Kasprian. “We wanted to see when it is possible to find changes in the fetal brain following exposure to alcohol. “

The study authors ruled out some fetal MRI scans due to structural brain abnormalities and poor image quality. The final group consisted of 26 scans of 24 alcoholic positive fetuses and a control group of 52 healthy peers of the same sex and age. At the time of imaging, the fetuses were 20 to 37 weeks old.

The CDC and previous studies have concluded that there is no safe amount of alcohol a woman can have during pregnancy or even while trying to get pregnant. Alcohol passes from the mother’s blood to her baby through the umbilical cord. Along with FAS, the CDC warns that drinking during pregnancy can also lead to miscarriage or stillbirth.

The researchers presented their findings at the annual meeting of the Radiological Society of North America.

South West News Service writer Mark Waghorn contributed to this report.


Comments are closed.