Mental Health Matters | Study bolsters link between prenatal nicotine exposure and ADHD
Pregnant women who have nicotine in their systems from smoking are more likely to have children who develop attention-deficit/hyperactivity disorder (ADHD), a new study suggests.
And the higher the level of nicotine in a pregnant woman’s blood, the greater her child’s risk of later being diagnosed with ADHD, researchers report in Pediatrics.
While not the first study to find an association between ADHD and in-utero exposure to nicotine, earlier research depended on mothers’ self-reports of cigarette smoking, rather than actual measurements of a nicotine breakdown product in the mothers’ blood.
To tease out any connection between nicotine and ADHD, the researchers turned to national databases kept in Finland, one of which stored blood samples from mothers-to-be and the other kept track of children who developed the attention disorder.
“We found, in a large nationwide sample that mothers who smoked during pregnancy, in particular those who were heavy smokers, had offspring with a fairly high risk for ADHD,” said senior study author Dr. Alan S. Brown, a professor of psychiatry and epidemiology at Columbia University in New York City. “That finding was after we controlled for a lot of potential variables that might account for the association.”
A 2018 government report put the rate of smoking among pregnant women who gave birth in the U.S. in 2016 at 7.2 percent. The rate is similar in Finland, Brown and his colleagues note.
The researchers were able to get data on the pregnant women’s nicotine levels through the Finish Maternity Cohort, which has serum samples collected early in pregnancy from more than 950,000 Finnish women.
For the new study, the researchers analyzed data on 1,079 children born between 1998 and 1999 who had been diagnosed with ADHD and 1,079 age-matched “controls” who did not have the condition.
