A large-scale Korean cohort study has found that maternal smoking before childbirth increases the risk of neurodevelopmental disorders in children by up to 52%. The study confirmed that even a small history of past smoking significantly elevates the risk, providing evidence that smoking cessation is necessary from the pre-pregnancy stage.
According to the medical community on the 28th, a joint research team — comprising Professor Chang Moon-young of the Department of Psychiatry at Korea University Guro Hospital, Professor Park Jun-bin of the Department of Cardiology at Seoul National University Hospital, Professor Han Kyung-do of the Department of Statistics and Actuarial Science at Soongsil University, and Professor Kim Jae-won of the Department of Child and Adolescent Psychiatry at Seoul National University Hospital — conducted a nationwide population-based mother-child cohort study analyzing data from 861,876 mother-infant pairs born between 2009 and 2018 who met the analysis criteria.
The researchers classified mothers into non-smoking, former smoking, and current smoking groups based on general health examination data from the National Health Insurance Service conducted within two years before childbirth. They then tracked the children for an average of more than eight years through 2021 to determine diagnoses of intellectual disability, autism spectrum disorder (ASD), and attention deficit hyperactivity disorder (ADHD).
The analysis showed that children of mothers with only a past smoking history had rates of intellectual disability 21% higher, ASD 29% higher, and ADHD 18% higher compared to children of non-smoking mothers. Children of mothers who were currently smoking faced even greater risks — 44% higher for intellectual disability, 52% higher for ASD, and 35% higher for ADHD.
Even in the light smoking group (pack-years less than 1.75), increased risks of 35% for intellectual disability, 55% for ASD, and 33% for ADHD were observed, revealing that "even small amounts are not safe."
"This is a study that confirmed the association between maternal smoking and neurodevelopmental disorders in children using Korea's largest mother-child cohort," Professor Chang Moon-young said. "Since even a small smoking history can affect a child's neurodevelopment, smoking cessation is important from the pre-pregnancy stage."
"It is necessary to establish social and medical support systems to reduce smoking among women of childbearing age," Chang added.
The study was published in the latest issue of the international journal *BMC Medicine*.
