Maternal smoking and neurodevelopmental outcomes in infants <29 weeks gestation: a multicenter cohort study

Objective To compare neurodevelopmental outcomes of preterm infants at 18–21 months corrected age (CA) whose mothers smoked during pregnancy to those whose mothers did not smoke. Study design Preterm infants born at <29 weeks of gestation and evaluated at 18–21 months CA were included. Primary outcome was a composite outcome of death or neurodevelopmental impairment (NDI). Results Of a total of 2760 infants, 699 met exclusion criteria. Of the remaining 2061 infants, 280 (13.6%) were exposed to maternal smoking and 1781 (86.4%) were not. The odds of the composite outcome of death or NDI (aOR 1.40; 95% CI: 1.03–1.91), NDI alone (aOR 1.43; 95% CI: 1.01–2.03), and Bayley-III motor score <85 (aOR 1.91; 95% CI: 1.31–2.81) were higher in exposed infants. Conclusions Exposure to maternal smoking was associated with adverse composite outcome of death or NDI, NDI alone and lower motor scores at 18–21 months CA.