Early-life antibiotics use and children’s developmental behaviors: a population-based cohort study

To examine the antibiotic use (any use within specific time windows), age of first use, cumulative frequency of use before 36 months of age, and cumulative duration of use in relation to cognitive development in the Chinese National Birth Cohort of 1,423 preschool children. Main caregivers reported children’s antibiotic use at 30 days, 6 months, 12 months and 36 months after birth. Cognitive development was assessed at age 3, using the Bayley Scales of Infant and Toddler Development, 3rd Edition. Linear regression models were used for statistical analysis. Antibiotic use from 6 to 12 months was associated with lower gross motor development scores. Earlier age at first use was associated with lower gross motor (β: -0.06; 95% CI: -0.10, -0.01) and composite motor scores (β: -0.09; 95% CI: -0.18, 0.00). Cumulative analyses showed that more frequent antibiotic use was linked to lower gross motor scores [at least once (β: -0.14; 95% CI: -0.28, -0.01); at least twice (β: -0.22; 95% CI: -0.40, -0.03)] and lower composite motor scores [at least once (β: -0.26; 95% CI: -0.51, -0.02); at least twice (β: -0.33; 95% CI: -0.65, -0.01)]. Longer duration of antibiotic use was associated with lower gross motor (β: -0.07; 95% CI: -0.14, -0.01) and lower composite motor scores (β: -0.16; 95% CI: -0.27, 0.04). Children’s antibiotic use before age 3 was correlated with lower gross motor scores. Specifically, higher frequency, earlier age at first use, and longer duration of use each predicted lower gross motor scores.