IMPORTANCE:
Maternal tobacco use during pregnancy (MTDP) persists across the globe. Longitudinal assessment of the association of MTDP with neurocognitive development of offspring at late childhood is limited.

OBJECTIVES:
To examine whether MTDP is associated with child neurocognitive development at ages 9 to 12 years.

DESIGN, SETTING, AND PARTICIPANTS:
This cohort study included children aged 9 and 10 years at wave 1 (October 2016 to October 2018) and aged 11 to 12 years at a 2-year follow-up (wave 2, August 2018 to January 2021) across 21 US sites in the Adolescent Brain Cognitive Development (ABCD) Study. Data were analyzed from June 2022 to December 2023.

EXPOSURE:
MTDP.

MAIN OUTCOMES AND MEASURES:
Outcomes of interest were neurocognition, measured by the National Institutes of Health (NIH) Toolbox Cognition Battery, and morphometric brain measures through the region of interest (ROI) analysis from structural magnetic resonance imaging (sMRI).

RESULTS:
Among 11 448 children at wave 1 (mean [SD] age, 9.9 [0.6] years; 5990 [52.3%] male), 1607 children were identified with MTDP. In the NIH Toolbox Cognition Battery, children with MTDP (vs no MTDP) exhibited lower scores on the oral reading recognition (mean [SE] B = -1.2 [0.2]; P <  .001), picture sequence memory (mean [SE] B = -2.3 [0.6]; P <  .001), and picture vocabulary (mean [SE] B = -1.2 [0.3]; P <  .001) tests and the crystallized cognition composite score (mean [SE] B = -1.3 [0.3]; P <  .001) at wave 1. These differential patterns persisted at wave 2. In sMRI, children with MTDP (vs no MTDP) had smaller cortical areas in precentral (mean [SE] B = -104.2 [30.4] mm2; P = .001), inferior parietal (mean [SE] B = -153.9 [43.4] mm2; P <  .001), and entorhinal (mean [SE] B = -25.1 [5.8] mm2; P <  .001) regions and lower cortical volumes in precentral (mean [SE] B = -474.4 [98.2] mm3; P <  .001), inferior parietal (mean [SE] B = -523.7 [136.7] mm3; P <  .001), entorhinal (mean [SE] B = -94.1 [24.5] mm3; P <  .001), and parahippocampal (mean [SE] B = -82.6 [18.7] mm3; P <  .001) regions at wave 1. Distinct cortical volume patterns continued to be significant at wave 2. Frontal, parietal, and temporal lobes exhibited differential ROI, while there were no notable distinctions in the occipital lobe and insula cortex.

CONCLUSIONS AND RELEVANCE:
In this cohort study, MTDP was associated with enduring deficits in childhood neurocognition. Continued research on the association of MTDP with cognitive performance and brain structure related to language processing skills and episodic memory is needed.