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Researchers say any alcohol or tobacco use during pregnancy can lead to a number of health issues for young children, including impacts on brain development. Getty Images
  • In a new study, researchers conclude that even low levels of alcohol and tobacco during pregnancy can affect an infant’s brain development.
  • The research builds upon past studies that have concluded that any alcohol or tobacco use during pregnancy can lead to numerous health issues for young children.
  • Despite the research, experts say there’s still a belief among segments of the population that occasional alcohol or tobacco use during pregnancy is OK.

Any exposure to alcohol or tobacco during pregnancy — even minimal amounts — can end up being unhealthy for a baby’s brain.

That’s according to a study published today by researchers from Columbia University in New York.

“Our study is the first to find that any level of prenatal alcohol exposure, whether it be only in the first trimester, low continuous throughout pregnancy, or high continuous exposure, are all associated with changes in newborn brain activity, measured using EEG (electroencephalography),” said Lauren C. Shuffrey, PhD, a postdoctoral fellow at Columbia University Medical Center and one of the study’s lead authors.

“We are first to report effects from any level of prenatal tobacco exposure on brain activity in newborns,” Shuffrey told Healthline. “These results are important since EEGs could be potentially used as an objective, noninvasive marker to examine associations with neurobehavioral development of risk for developmental disorders at later ages.”

“These results also suggest that research still hasn’t determined a safe level of alcohol or tobacco during pregnancy,” she added.

Researchers studied 1,739 mother-newborn pairs from December 2011 until August 2015.

Participants were from South Africa and the Northern Plains region of the United States.

Children were born between 37 and 41 weeks of gestation, single births, and the mothers couldn’t use psychiatric medication during pregnancy.

The infants’ brain activity was measured during sleep.

“What they were getting are these full-term babies who are otherwise healthy,” said Dr. Susan Walley, a professor of pediatrics at the University of Alabama at Birmingham. “This is really a well-designed study, to say we see observable differences in babies with even low exposure to alcohol and tobacco.”

“EEG patterns in newborns have the power to predict development outcomes,” Walley told Healthline.

Numerous past studies have already determined that prenatal alcohol exposure (PAE) and prenatal tobacco exposure (PTE) during pregnancy can have consequences on a child’s health.

In today’s study, researchers noted that “PAE is the leading cause of preventable intellectual disability, and smoking during pregnancy is one of the most modifiable causes of perinatal morbidity and mortality.”

Researchers concluded that even a small amount of exposure can be damaging not long after birth.

“The (graphics) really show the difference in brain activity,” said Walley, who read the report before it was released. “This is after the baby is born and they’re showing a big difference, even with low levels of (alcohol and tobacco) use.”

There have been other studies using EEGs to measure associations between PAE and PTE, but those projects used smaller sample sizes and didn’t have as wide a scope as the most recent study.

In January 2020, a study published in the International Journal of Epidemiology disputed other research that concluded small amounts of alcohol during pregnancy might be safe.

Researchers in this study analyzed 23 previously published studies and concluded using alcohol during pregnancy results in children with poorer cognitive function and increased risk of lower birth weight.

They also pointed out that the alcohol industry minimizes and routinely omits evidence concerning the risks of alcohol during pregnancy.

“With alcohol, I think people still believe there’s potential for low-level use,” Walley said. “These results show an objective sign of negative effects to brain development.”

Walley said there’s a surprising lack of specific data when it comes to the need for total abstinence during pregnancy.

Plus, access to that data isn’t always forthcoming or available. And, if it is, there isn’t as much access to assistance.

“In lower socioeconomic areas, there’s no access to smoking cessation methods,” she said. “We know there are still pregnant women who are smoking.”

The list of possible problems in infants whose mothers have used alcohol or tobacco is long, including decreased IQ scores and an auditory deficit leading to impaired verbal, memory, language, and auditory processing, said Dr. Rashmi Byakodi, a physician who’s also a health and wellness writer.

“Studies have revealed that maternal consumption of alcohol or smoking during pregnancy might alter the autonomic nervous system,” Byakodi told Healthline.

“Newborns whose mothers smoked during pregnancy had lower beat-to-beat heart rate variability in quiet sleep,” she added. “Infants whose mothers consumed alcohol had lower global heart rate variability in active sleep.”

Researchers are following up with participants of today’s study.

“This is important for two reasons,” Shuffrey said. “First, it lays the groundwork for EEGs to be potentially used as a marker of later development issues attributable to prenatal alcohol or tobacco exposure.”

“Secondly, although everyone knows alcohol and tobacco are bad when pregnant, 1 in 10 women drink during pregnancy in the U.S. and smoking is one of the leading causes of morbidity/mortality in mother-infant dyads,” Shuffrey said.

“There have been media reports that an occasional glass of wine, or even a drink per day, are OK during pregnancy,” Shuffrey said. “However, our data suggests that there is not a safe level to drink or smoke during pregnancy.”