Smoking during pregnancy may not cause ADHD in children after all

Press release issued: 7 April 2022

A new systematic review and meta-analysis published in the scientific journal Addiction and led by University of Bristol researchers shows that maternal prenatal smoking is associated with offspring attention-deficit hyperactivity disorder (ADHD) but is unlikely to be the cause of it.

The review looked at 46 prior studies that assessed the association between maternal prenatal smoking and offspring ADHD diagnosis. The review specifically included studies accounting for genetic effects, in addition to conventional approaches.

Some of those studies had a low risk of bias (meaning they are unlikely to give misleading results) and were able to take into account genetic effects. Those studies indicate that shared genetics plays a substantial role in the association of offspring ADHD with prenatal smoking. This is supported by a previous systematic review based on genetically informed designs which also concluded that the association between maternal prenatal smoking and ADHD is explained by shared genetics.

Read the full University of Bristol press release

Paper: ‘Prenatal smoking, alcohol and caffeine exposure and offspring externalizing disorders: a systematic review and meta-analysis’ by Elis Haan et al. in Addiction.