SMOKING IN PREGNANCY AND DISRUPTIVE BEHAVIOUR IN 3-YEAR OLD BOYS AND GIRLS: AN ANALYSIS OF THE UK MILLENNIUM COHORT STUDY
- 1 Department of Health Sciences, University of York, United Kingdom;
- 2 Institute for Juvenille Research, Department of Psychiatry, University of Illinois at Chicago, United States
- Correspondence to: Jayne Hutchinson, University of Leeds, Nutritional Epidemiology Group, Faculty of Medicine, University of Leeds, Room 8.01, Level 8, Worsley Building, Leeds, LS2 9JT, United Kingdom; umjh{at}leeds.ac.uk
- Received 26 February 2009
- Accepted 17 August 2009
- Published Online First 3 November 2009
Abstract
Background: Maternal smoking during pregnancy has been consistently associated with disruptive behaviour in male offspring, however results for girls are inconsistent and little is known about emergent patterns in young children. Additionally, it is unclear whether maternal smoking is independently associated in offspring with hyperactivity-inattention or only when it co-occurs with conduct problems. Further, few studies have controlled for a broad range of maternal psychosocial problems.
Methods: We analysed associations between self-reported smoking in pregnancy and maternal reports of externalising behaviour in more than 13,000 3-year old boys and girls in the UK Millennium Cohort Study. Conduct and hyperactivity-inattention problems were assessed using the Strength and Difficulties Questionnaire.
Results: Boys whose mothers persistently smoked throughout pregnancy were at significant risk of conduct and hyperactivity-inattention problems compared to sons of non-smokers: the effect was stronger for heavy smokers. After excluding children with co-occurring problems, conduct-only problems remained a significant risk for sons of heavy smokers, and hyperactivity-inattention-only for sons of light or heavy smokers. Daughters of light or heavy smokers were at significant risk of conduct-only problems. Relative to non-smokers, daughters of pregnancy quitters had significantly reduced odds of having conduct or co-occurring problems, although only 79 and 20 girls met these criteria, respectively. All findings were robust to controlling for key social and psychosocial factors.
Conclusions: Associations between maternal smoking during pregnancy and disruptive behaviour in 3 year old children vary by sex, smoking status and whether or not conduct or hyperactivity problems occur together or separately.
