Drinking Changes Baby’s Brain Structure

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Most experts recommend that women drink no alcohol during pregnancy. Oleg Breslavtsev/Getty Images
  • Researchers say even an occasional drink can alter the brain structure of a developing fetus.
  • Their study is the latest research that indicates that even small amounts of alcohol during pregnancy can affect a baby before it is born.
  • Experts say alcohol during pregnancy can manifest into fetal alcohol syndrome disorders, which can lead to learning and behavioral issues.

Even small amounts of alcohol can cause changes to a developing baby’s brain structure.

That’s the conclusion of a study presented today at the annual meeting of the Radiological Society of North America (RSNA).

For years now, women have heard information about how even the occasional drink while pregnant can harm their infants.

For the new study, which hasn’t been published yet in a peer-reviewed journal, researchers used MRI images to evaluate fetal brains in babies exposed to alcohol during their mother’s pregnancy.

The scientists reported that even low to moderate alcohol consumption can change the baby’s brain structure and delay brain development.

The most recent study looked at brain MRIs for 24 fetuses with prenatal alcohol exposure.

The mothers were between 22 and 36 weeks pregnant at the time of the MRI and the fetuses were matched 1:1 with healthy fetuses not exposed to alcohol.

The scientists determined alcohol use based on surveys completed by the mothers anonymously. Overall, 17 mothers reported drinking relatively infrequently, with an average alcohol consumption of less than one drink per week.

Other responses indicated:

  • Three mothers indicated drinking one to three drinks per week
  • Two mothers drank four to six weeks per week
  • One mother consumed an average of 14 drinks per week
  • Six mothers reported at least one binge-drinking episode

The scientists reported that in fetuses with alcohol exposure:

  • The total maturation score was significantly lower
  • The temporal and right superior temporal sulcus, regions of the brain involved in social cognition, audiovisual integration, and language perception and development were affected

The researchers say it isn’t clear how these brain changes will affect the babies after birth and won’t know until the children are assessed when older.

However, they do assume the changes related to cognitive and behavioral difficulties will continue into childhood.

“This study provides additional evidence that the ingestion of alcohol affects neural development,” said Dr. G. Thomas Ruiz, the OB/GYN lead at MemorialCare Orange Coast Medical Center in Fountain Valley, California. “The fetal MRI is just the first study to document the neural changes in utero.”

“This study strengthens our evidence to counsel pregnant women to avoid alcohol consumption during pregnancy,” Ruiz told Healthline. “We need to determine if there is a critical volume of alcohol that will create a negative impact. It is unlikely that one sip of champagne on Thanksgiving or New Year’s Eve will have the same negative effect on neural development that a daily alcoholic beverage does.”

Many medical experts say that fetal alcohol spectrum disorders (FASD) can lead to learning disabilities, behavioral problems, or speech and language delays.

This study concludes that minimal alcohol consumption during pregnancy might cause harm to the unborn child.

“I do not believe that occasional alcohol consumption is OK during pregnancy,” Dr. Jessica Auffant, an OB-GYN for Orlando Health Physician Associates in Florida, told Healthline. “Although small amounts may lead to no known consequences, small amounts can cause irreversible fetal changes that we do not know about yet. This study helps confirm this recommendation.”

However, even among the medical community, there isn’t a universal belief that small amounts of alcohol exposure can cause problems.

A report issued in 2017 found that “there is no evidence that fetal alcohol spectrum disorder occurs in babies born to women who drink occasionally or moderately during pregnancy.”

The researchers here also indicated that only 4% to 5% of children of women who drink heavily are born with FASD.

They concluded that “there is no well-accepted scientific evidence that low or moderate levels of alcohol consumption during pregnancy – even in the first few days or weeks after conception- cause FAS or other associated problems.”

In 2020, Dr. Howard E. LeWine, wrote in an article for Harvard Health Publishing that “Minimal alcohol use during the first trimester doesn’t appear to increase the risk for high blood pressure complications, or premature birth or low birth weights.”

Fetal alcohol spectrum disorders are a range of disorders caused by alcohol exposure before birth.

The disorders can be mild or severe and can be physical or mental.

Alcohol can affect a developing baby before a woman knows she is pregnant, according to the Centers for Disease Control and Prevention (CDC).

When a mother drinks alcohol, it enters her blood system and is passed to the baby through the umbilical cord.

However, it is never too late to stop drinking if you are pregnant. Because a baby’s brain growth continues throughout the pregnancy, stopping can improve the baby’s health.

“We do not know what amount of alcohol is safe and does not pose a risk; therefore should be avoided,” Auffant said. “It is known that alcohol can affect babies at any time during pregnancy, but it is likely more dangerous in the first trimester when the organs develop.”

According to the CDC, symptoms of FASD include:

  • Low body weight
  • Poor coordination
  • Hyperactive behavior
  • Difficulty with attention
  • Poor memory
  • Difficulty in school (especially with math)
  • Learning disabilities
  • Speech and language delays
  • Intellectual disability or low IQ
  • Poor reasoning and judgment skills
  • Sleep and sucking problems as a baby
  • Vision or hearing problems
  • Problems with the heart, kidneys, or bones
  • Shorter-than-average height
  • Small head size
  • Abnormal facial features, such as a smooth ridge between the nose and upper lip

“Alcohol consumption mechanisms appear to be layered, with both immediate and long-term effects,” said Dr. Kecia Gaither, the director of Perinatal Services/Maternal Fetal Medicine at NYC Health + Hospitals/Lincoln in the Bronx, New York.

“We do not know what dose of alcohol starts the trail of damage,” Gaither told Healthline. “Given such, physicians, me included, advise patients not to drink alcohol during pregnancy. It is one of the few potential dangers to fetuses where effects can be mitigated simply by not imbibing.”