Smoking in Pregnancy and Child ADHD

Abstract

BACKGROUND AND OBJECTIVE:There is a well-documented association between maternal smoking during pregnancy and offspring attention-deficit/hyperactivity disorder (ADHD). The degree to which this reflects causal intrauterine effects or is due to unmeasured confounding is not clear. We sought to compare the association between maternal smoking during pregnancy and offspring ADHD with the associations with paternal smoking, grandmother's smoking when pregnant with mother, and maternal smoking in previous pregnancies. Each of these exposures is expected to be influenced by much of the same confounding factors as maternal smoking during pregnancy, but cannot have direct intrauterine effects. A sibling control design was also used.

Maternal Smoking and Attention-Deficit/Hyperactivity Disorder in Offspring: A Meta-analysis

“…Keyes et al 45 found that there was no association between paternal smoking and offspring ADHD after adjustment for several covariates. In contrast, Gustavson et al 36 reported that paternal smoking increased the risk of ADHD by 1.23 times. We searched the databases, and 7 related studies were included for further analysis.…”

“…It was reported that the prevalence of parental ADHD was higher in children with ADHD, 34 and children born to parents with ADHD had an increased risk of ADHD. 42 We also noted that the authors of studies with a sibling design did not show the relationship between maternal smoking and ADHD, 20,27,36 suggesting a key role for genetics in the development of ADHD. In those sibling-design studies, the authors suggested that the family context and genetic factors are similar in siblings.…”

“…In 5 of the selected studies, 12,13,20,22,27 authors reported the ORs separately for boys and girls, including 634 229 boys and 576 170 girls. In the 3 cohort studies, 20,27,36 the authors used sibling analysis to control for shared genetic and social confounding. The sample size of the studies ranged from 260 to 982 856.…”

“…28 In 12 of the selected studies, researchers adopted the diagnostic criteria from the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised (DSM-III-R) 30,31,34,35 or the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), 15, 23 -25, 29, 32, 33 whereas the International Classification of Diseases, 10th Revision (ICD-10) was used as the diagnostic method for ADHD in only 3 studies. 20,27,36 In 2 studies, the authors chose measures to assess ADHD, such as the Strengths and Difficulties Questionnaire (SDQ) 13,21 and Child Behavior Questionnaire (Rutter B2). 12 The information about smoking was generally collected by interviews or according to related registers.…”

Maternal Perinatal and Concurrent Anxiety and Mental Health Problems in Early Childhood: A Sibling‐Comparison Study

“…The comparison of siblings of mothers who smoked during one pregnancy but not the other controls for many familial confounds, thus providing a far more stringent test of association than most other research designs. With this method it has been shown that smoking is systematically linked to lower birth weight in the offspring but does not appear to influence the offspring's risk for mental health problems (Gustavson et al, 2017;Kuja-Halkola, D'Onofrio, Larsson, & Lichtenstein, 2014;Lahey & D'Onofrio, 2010).…”