Even low levels of alcohol use during early pregnancy are associated with greater risks of anxiety, depression and behavior problems in children. Slightly higher use, gauged at 36 drinks in the first six to seven weeks of pregnancy, is associated with a 25% increased likelihood of attention deficit hyperactivity disorder, according to a study by collaborators at the Medical University of South Carolina and the University of Sydney in Australia.
Lindsay Squeglia, Ph.D., associate professor in the Department of Psychiatry and Behavioral Sciences at MUSC, said most studies of alcohol use during pregnancy have focused on heavy drinking that can result in fetal alcohol spectrum disorders, which affect the central nervous system and can lead to problems with learning, communication, impulse control and daily life activities. Fetal alcohol syndrome is the most extreme outcome, however.
"There aren't a ton of kids with fetal alcohol syndrome," Squeglia said. "But there are a lot of people who use alcohol at low levels during pregnancy."
For Squeglia's collaborators in Australia, the findings bolster the argument in favor of warning labels on alcoholic beverages in Australia and New Zealand, where a joint food regulation ministry voted earlier this year to make such warning labels mandatory.
The collaboration began in February 2019 when Briana Lees, then a graduate student, came to study for one month at MUSC from Australia. Squeglia introduced her to the national Adolescent Brain Cognitive Development longitudinal study. The study, conducted at 21 sites across the U.S., including MUSC, includes comprehensive questionnaires that cover everything from diet to sleep to schooling as well as regular brain scans of the children in the study. Children entered the study at ages 9 or 10 and will be followed for 10 years. The resulting data is available to researchers anywhere in the world.
Coming from Australia, where 25% of pregnant women continue to drink alcohol, Lees was interested in what the ABCD data could show about the effects of prenatal exposure to alcohol. It was a good complement to Squeglia's work.
"Almost my whole career since graduate school, I've been looking at how alcohol affects the developing adolescent brain. Having a better understanding of how it's affecting the brain prenatally is the other end of the age spectrum," Squeglia said.
Squeglia said the brain scans showed that children who had been prenatally exposed had larger brains. And while that might sound like a good thing, it could mean that these children's brains haven't been properly engaged in pruning, the process by which the brain gets rid of redundant or unnecessary connections in early childhood and again in adolescence to create more efficient neural pathways.
Lees was lead author on the current paper, published in the American Journal of Psychiatry, as well as on a previous paper in the journal Drug and Alcohol Dependence that found that children who were prenatally exposed to alcohol were more likely to experiment with alcohol at ages 9 and 10.
The collaboration isn't ending with these papers, however. Squeglia was awarded a Fulbright Research Award earlier this year and will use it to further develop the transnational relationship between MUSC and the Matilda Centre for Research in Mental Health and Substance Abuse at the University of Sydney.
Squeglia said they found that the Matilda Centre and MUSC's Youth Collaborative were working along the same lines on so many projects that it made sense to start working more closely together.
She will be traveling to Australia at some point to work with the Matilda Centre faculty in person, although the COVID-19 pandemic has pushed back travel plans.
In the meantime, she's excited that the next wave of data from the ABCD study is about to be released. Now, in addition to the cross-sectional data available by comparing trends across almost 12,000 children, there will be longitudinal data allowing for the tracking of growth and development over time. Squeglia said she'd like to uncover the resilience factors that protect children.
"What predicts which kids who are prenatally exposed but didn't have bad cognitive outcomes, versus those who did?" she said.
