Children exposed to maternal smoking before birth are more likely to experience behavioral and mental health challenges, according to a large study funded by the National Institutes of Health's Environmental influences on Child Health Outcomes (ECHO) Program.
While previous research had linked prenatal smoking to acting out or rule-breaking, it was less clear whether smoking during pregnancy also affects broader mental health outcomes and whether effects differ by sex. The new study sheds light on these questions, examining thousands of children across the U.S. and identifying periods when exposure may be most impactful.
"These findings show that prenatal nicotine exposure can affect more than just acting-out types of behavior problems—it can influence children's overall mental health and experiences of both emotional and behavioral problems at the same time," said Kristine Marceau, PhD, of Purdue University. "Understanding when kids are most vulnerable can help families and healthcare providers provide support at the right time."
Researchers analyzed data from 16,335 children ages 1 to 18 from 55 ECHO Cohort Study Sites. Behavioral assessments measured emotional and behavioral symptoms using standardized questionnaires.
Key Findings
- Widespread Impact: Children exposed to prenatal smoking were more likely to have multiple mental health or behavioral symptoms at the same time.
- Critical Windows: The strongest effects appeared in early childhood (under age 7) and early puberty (ages 9–12).
- Similar Effects for Boys and Girls: Both sexes were affected in comparable ways, with slightly higher symptom levels in boys only at ages 13–14.
- Independent of Family Background: Associations persisted even after considering family history and other environmental factors, such as maternal age, education, and additional substance exposures.
Future studies could take a closer look at the timing, amount, and frequency of smoking during pregnancy. Researchers could also work to better understand which effects are due to smoking itself—rather than other family factors—and how nicotine and other chemicals in smoke may affect how children grow and develop.
This collaborative research , titled "Prenatal Smoking and Child Psychopathology Associations by Age and Sex in the ECHO Cohort," is published in Development and Psychopathology .
