Association of maternal nighttime artificial light exposure with children’s neurodevelopment: A Chinese birth cohort study

Background: The association between maternal artificial light at night (ALAN) exposure and children’s neurodevelopmental delay remained unexplored. Methods: This birth cohort study, conducted in Foshan City, Southern China from 2019 to 2023, included 76,077 participants. Maternal exposure to ALAN was estimated based on participants’ residential addresses using nighttime satellite imagery. Logistic regression models were applied to examine the associations between maternal ALAN exposure during different trimesters and neurodevelopmental delay in children. Subgroup analyses were performed to identify potential effect modifiers of the relationship between maternal ALAN exposure and children’s neurodevelopmental delay. Results: For each 10 nW/cm²/sr increase in maternal ALAN exposure, the adjusted ORs for neurodevelopmental delay were 1.37 (95% CI: 1.33, 1.41) in the first trimester, 1.36 (95% CI: 1.32, 1.40) in the second, and 1.37 (95% CI: 1.33, 1.41) in the third, respectively. Domain-specific analyses revealed similar associations, with the strongest effect observed for ALAN exposure in the first trimester on gross motor delay (OR = 1.30; 95% CI: 1.26, 1.33). Threshold effect analyses further revealed a nonlinear dose‑response pattern, with a significant increase in risk only within a middle exposure range (approximately 20–40 nW/cm²/sr) for all trimesters. Subgroup analyses suggested that maternal educational attainment, employment status, and child sex may modify the association between maternal ALAN exposure and neurodevelopmental delay. Conclusion: Maternal exposure to ALAN was associated with an increased risk of neurodevelopmental delay in children, along with delays in domain-specific neurodevelopment.