one group compared to the other group, or in different means of assessment of the disorder (parental vs personal report), the LORs employed were for ADHD diagnosis and not based on particular criteria, sub-diagnosis, or symptom count. Maternal illicit drug use during pregnancy was not accounted for in either domain; however, although illicit drug use was associated with attention problems, it was not associated with an increase in externalizing disorders in offspring (Irner, 2012). A substantial proportion (12%–43%) of mothers who drink while pregnant also smoke but there are mixed results demonstrating increased rates of disorders attributable to smoking (Han et al., 2015; Hill et al., 2000), or no significant increase in risk after covarying for other risk factors (Knopik et al., 2004; Mick, Biederman, Faraone, Sayer, & Kleinman, 2002). Slightly fewer than half of the PAE studies established maternal consumption during pregnancy via an interview requiring retrospective recall, which might be considered a weakness. However, one study has shown that maternal retrospective (14 years) recall of consumption during pregnancy was a better predictor of attention and externalizing behavior problems in their offspring than consumption amounts reported during the pregnancy (Hannigan et al., 2010).
