Drinking or smoking while pregnant may affect newborn's brain development

Researchers found that drinking or smoking of any level while pregnant influenced the brain development of the mothers' newborns. Negative long-term effects of excessive prenatal alcohol or tobacco exposure (or both) increase the risk for multiple adverse outcomes.

The study examined the link between prenatal exposure to alcohol and tobacco smoking and brain activity in newborns. The researchers conducted an electroencephalogram (EEG, which is a noninvasive test of brain function and activity reflecting electrical activity in the brain's cortex and is commonly used to examine and predict effects of in utero exposures and associations with development of the brain at later ages) on 12 regions on the newborns' scalps while they were sleeping.

The findings suggested drinking or smoking in early stages and then quitting, or doing so at low, moderate or high levels all impacted newborn brain development.

They found that infants whose moms smoked during pregnancy had decreased activity in the right-central area of their brains, compared with newborns who weren't exposed to tobacco while in the womb.

Also, newborns whose mothers quit drinking before the second trimester, or were in the low to high continuous drinking groups, had increased low frequency EEG power in the left temporal section of their brain compared to infants with no prenatal alcohol exposure.

"Already we can see there was an alteration in the development of brain processes that can be quantified during sleep when babies are just a few days of age," said senior author William P. Fifer, a professor of medical psychology at Columbia University Irving Medical Center in New York City. "Babies of those moms who even had low levels of alcohol or tobacco exposure still had some alterations in the brain activity."

Previous studies have shown the effects alcohol and tobacco exposure have on specific areas of the brain involved in the baby's ability to regulate their heart rate, respiration, blood pressure and temperature, Fifer said.

Prenatal alcohol exposure is the leading cause of preventable intellectual disability and smoking during pregnancy is one of the most modifiable causes of post-birth disease and death.

"All of those are extremely important to survive those first few months," he added.