Impact of Maternal Smoking on Offspring Neurodevelopmental Disorders in Korea

Overview

This large nationwide Korean cohort study found that maternal smoking identified through prenatal health assessments is associated with increased risks of neurodevelopmental disorders in offspring, particularly ADHD. The study utilized prospectively collected smoking data and national registry diagnoses to clarify dose–response relationships and control for confounders.

Background

Neurodevelopmental disorders such as intellectual disability, autism spectrum disorder (ASD), and attention-deficit/hyperactivity disorder (ADHD) have lifelong impacts and originate during prenatal brain development influenced by genetic and environmental factors. Maternal smoking is a modifiable prenatal exposure linked to adverse perinatal outcomes and potential neurodevelopmental disruption via neurotoxic effects. Prior studies on maternal smoking and neurodevelopmental disorders have been inconsistent due to methodological limitations, including small samples, recall bias, and insufficient confounder control. This study aimed to address these gaps using a large Korean mother–child cohort with prospectively collected smoking data and validated clinical diagnoses.

Data Highlights

Key Findings

• Maternal smoking status was prospectively collected from NHIS health examinations within 2 years before delivery, minimizing recall bias.
• Offspring neurodevelopmental disorders assessed included intellectual disability, ASD, and ADHD, identified via national registries and insurance records.
• Current maternal smoking was associated with a higher risk of ADHD in offspring, with a dose–response relationship observed based on cumulative pack-years.
• Associations with intellectual disability and ASD were weaker or less consistent compared to ADHD.
• Analyses adjusted for multiple maternal and pregnancy-related confounders, enhancing validity of findings.
• Stratified analyses explored potential effect modification by child’s sex.

Clinical Implications

These findings reinforce the importance of identifying and addressing maternal smoking before and during pregnancy as a modifiable risk factor for offspring neurodevelopmental disorders, especially ADHD. Clinicians should prioritize smoking cessation interventions in women of reproductive age and incorporate smoking status assessments into prenatal care. Public health strategies targeting smoking reduction in this population may help mitigate long-term neurodevelopmental risks in children.

Conclusion

This comprehensive Korean cohort study provides robust evidence linking maternal smoking prior to delivery with increased risks of neurodevelopmental disorders in offspring, particularly ADHD, highlighting the critical need for effective prenatal smoking cessation efforts.

References

1. Korean Mother-Child Cohort Study -- Impact of Maternal Smoking on Offspring Neurodevelopmental Disorders