Maternal Sleep Disorders Increase Risk of Neurodevelopmental Disorders in Children

Led by Tak Kyu Oh and In-Ae Song from Seoul National University Bundang Hospital, the study utilized South Korea’s extensive National Health Insurance Service database, which tracks nearly all medical interactions in the country. The researchers examined every live birth recorded between January 1, 2008, and December 31, 2012, ultimately including 1,993,494 children in their analysis. By using the International Classification of Diseases for diagnoses, they tracked maternal sleep disorders and childhood neurodevelopmental outcomes over a follow-up period extending up to fifteen years, concluding at the end of 2023.

Maternal exposure to sleep disorders was categorized based on specific diagnostic codes encompassing conditions such as insomnia, obstructive sleep apnea, and restless legs syndrome. The researchers distinguished between disorders diagnosed before and during pregnancy. This temporal classification allowed the investigation of whether the timing of a sleep disorder diagnosis affected the association with childhood neurodevelopmental issues, a question relevant to understanding maternal influences on fetal brain development.

Of the nearly two million children included, 33,229 (approximately 1.7 percent) were born to mothers with a diagnosed sleep disorder. To address potential confounding variables such as maternal age, income, and health conditions, the researchers employed propensity-score matching, comparing 33,183 children of mothers with sleep disorders to 160,131 unexposed children.

The results revealed that children whose mothers had sleep disorders faced a 36 percent higher risk of being diagnosed with long-term neurodevelopmental conditions, which include intellectual disabilities and autism spectrum disorders. The hazard ratio calculated was 1.36, with high statistical significance. This means that among children with similar characteristics, those born to mothers with sleep disorders were diagnosed with neurodevelopmental issues at a higher rate over the follow-up period.

Further analysis revealed that disorders diagnosed prior to pregnancy had a stronger association (hazard ratio of 1.31) compared to those diagnosed after conception (1.18). Maternal insomnia increased risk by 28 percent, sleep apnea by 32 percent, and restless legs syndrome by 48 percent, although the latter had a wider confidence interval due to fewer cases.

The authors suggest several biological pathways that might explain how maternal sleep issues affect fetal brain development, including elevated stress hormones and potential oxygen deprivation due to sleep apnea. Previous animal studies have shown that sleep deprivation can lead to neurobehavioral abnormalities in offspring.

While the study's large scale is commendable, it is important to note that observational research cannot establish causal relationships. Sleep disorders may be linked to other health issues that influence brain development, and the accuracy of diagnostic codes can vary. Despite these limitations, the study has significant public health implications, as sleep disorders are common and treatable conditions among women of childbearing age.

The authors suggest that screening and treating sleep disorders before and during pregnancy could represent a valuable intervention for improving children's brain health. As the link between maternal sleep and child outcomes strengthens, effective management of maternal sleep health could be integrated into preconception and prenatal care, potentially influencing the development of millions of children globally.