Many studies have shown the association between maternal prenatal smoking and a child’s externalizing disorders such as attention deficit hyperactivity disorder (ADHD). However, it is uncertain whether this relationship is causal.
Scientists at the University of Bristol conducted a systematic review to determine:
- If the study supports a causal role of maternal prenatal substance use on offspring externalizing disorders diagnosis.
- Whether these associations differ across externalizing disorders.
For this review, scientists 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 and conventional approaches.
Some of the studies had a low risk of bias- they are unlikely to give misleading results and were able to consider genetic effects. Those studies indicate that shared genetics plays a vital role in associating offspring ADHD with prenatal smoking.
This review supported previous studies based on genetically informed designs, which also concluded that the association between maternal prenatal smoking and ADHD is explained by shared genetics.
Lead author Dr. Elis Haan, an Honorary Research Associate at Bristol’s School of Psychological Science, says, “Our systematic review shows no causal effect between maternal prenatal smoking and offspring ADHD diagnosis. However, pregnant women should still be advised not to smoke during pregnancy, as prenatal smoking has harmful effects on other child health outcomes.”
- Elis Haan et al. Prenatal smoking, alcohol and caffeine exposure and offspring externalizing disorders: a systematic review and meta-analysis. DOI: 10.1111/add.15858