Objective: To study whether prenatal smoking only relates to externalizing problems or whether it is associated with both internalizing and externalizing problems from childhood into late adolescence.
Method: Child Behavior Checklist-derived, parent-reported internalizing and externalizing problems of 396 children were longitudinally assessed at ages 5, 10 to 11, and 18 years. The influence of self-reported prenatal smoking on the course of internalizing and externalizing problems over these ages was assessed, controlling for the co-occurrence of internalizing and externalizing problems and co-occurring pre- and perinatal risk factors, demographic characteristics, maternal mental health, and child social and attention problems.
Results: Children whose mothers had smoked during pregnancy had increased levels of both internalizing and externalizing problems over the period of ages 5 to 18 years when compared with children whose mothers did not smoke during pregnancy. These associations remained significant after controlling internalizing for externalizing and vice versa and possible confounding variables.
Conclusions: Maternal smoking during pregnancy is a predictor of internalizing as well as externalizing psychopathology in offspring. The association between prenatal smoking and internalizing and externalizing problems persists throughout childhood and late adolescence.