Previous research has linked prenatal smoking and "externalising" behaviours, such as aggression, hyperactivity and delinquency, which may begin in childhood and persist through early adulthood, report Dr. Pol AC van Lier and colleagues at VU University of Amsterdam.
Now, they suggest that internalising behaviours be added to the list, according to their report in the Journal of the American Academy of Child and Adolescent Psychiatry.
The investigators evaluated parental responses to the Dutch version of the Child Behaviour Checklist completed by the parents of 396 children (201 boys) when their children were five, 10 to 11, and 18 years old.
About seven percent of the mothers reported smoking 10 or more cigarettes per day during pregnancy. The 28 children of these mothers comprised the "exposed" group.
Compared with children who were not exposed to tobacco smoke in utero, at each age assessment the exposed children had higher average scores for internalising behaviours. As expected, the exposed group also had higher average scores for externalising behaviours at each age.
These findings held when the investigators accounted for other factors potentially associated with development of such behaviours, including other social or attention problems, maternal mental health, and family demographics.
These findings suggest "prenatally exposed children had significantly increased internalising and externalising problems from childhood into late adolescence," van Lier and colleagues conclude.
"Our results also suggest that clinicians should be aware when working with children whose mothers smoked during pregnancy." While prenatal smoking may have a direct effect or may be a marker for a genetic vulnerability, these children are still at risk for both types of psychopathology.