Yan He, Jian Chen, Li-Hua Zhu, Ling-Ling Hua, and Fang-Fang Ke

Journal of Attention Disorders 1 –11 , 2017 DOI: 10.1177/1087054717696766

This article describes a meta-analyses of studies which examined the potential effects of maternal smoking on the risk of childhood ADHD. A prior meta-analysis in 2005 (Langley, Rice, Van den Bree, & Thapar, 2005) found a strong association between maternal smoking and subsequent development of childhood ADHD in exposed offspring. Several recent individual studies also found an association be, tween maternal smoking and childhood ADHD, but one prospective study (Ball et al., 2010) did not find such an association. Therefore, given the length of time since the last meta-analysis and the one negative study noted above, highlighted the need for an updated meta-analysis. The authors employed fairly standard meta-analysis guidelines via the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement, which included a selection of studies, data extraction and assessment of study quality. The risk ratios (RRs) and 95% CIs reported in the individual studies were pooled across studies to examine the potential association of maternal smoking during pregnancy and childhood ADHD risk. The authors also examined for presence of publication bias and changing association over time. 265 studies were originally identified, with 12 meeting the stringent criteria to be included in the meta-analysis. The main finding of the analysis was the maternal smoking was modestly association with an increased risk of ADHD in children (pooled RR = 1.58, 95% CI = [1.33, 1.88]) and this association seemed to increase over time (by examining publication year); no significant publication bias was seen. The authors that the association they observed was not as robust as the one seen by Langley et al. for several reasons: their including a larger number of trials, which were limited to those with prospective and not case-controlled desi This meta-analysis is important for clinicians as it highlights the importance of the need to caution their patients as to potential risks of offspring developing ADHD in mothers who smoke during pregnancy.

Ball, S. W., Gilman, S. E., Mick, E., Fitzmaurice, G., Ganz, M. L., Seidman, L. J., & Buka, S. L. (2010). Revisiting the association between maternal smoking during pregnancy and ADHD. Journal of Psychiatric Research, 44, 1058-10

Langley, K., Rice, F., Van den Bree, M. B., & Thapar, A. (2005). Maternal smoking during pregnancy as an environmental risk factor for attention deficit hyperactivity disorder behaviour. A review. Minerva Pediatrica, 57, 359-37