Perinatal antibiotic exposure and infant sleep behavior: findings from the ABERRANT study

BACKGROUND: Antibiotics administered during pregnancy and delivery can disrupt the developing infant intestinal microbiome, but their effects on infant sleep remain poorly understood. Given the critical role of sleep in early neurodevelopment, alterations in sleep during this sensitive developmental period may have lasting consequences for later cognitive and behavioral outcomes. METHODS: In a prospective birth cohort study, associations between indirect antibiotic exposure (maternal antibiotic use during the third trimester of pregnancy or during delivery) and parent-reported sleep at 2 and/or 6 months were examined in 192 infants (46% females) using linear mixed-effects models. RESULTS: Indirect antibiotic exposure during delivery was associated with a higher daytime-to-nighttime sleep ratio, reflecting relatively greater daytime sleep duration compared with nighttime sleep at both ages. Indirect antibiotic exposure during delivery was also associated with fewer nighttime awakenings, while no significant associations were observed for sleep latency. Effect sizes were small to moderate, suggesting subtle alterations in sleep behavior rather than overt sleep disturbance. CONCLUSION: These findings suggest that indirect perinatal antibiotic exposure may be associated with altered sleep behavior in infants and warrant further investigation into potential underlying mechanisms, including alterations of the developing microbiome. IMPACT: Indirect antibiotic exposure during delivery is associated with subtle differences in sleep behavior at 2 and 6 months. This study extends existing literature on perinatal antibiotic exposure by examining early sleep outcomes, an understudied domain despite the importance of sleep for neurodevelopment and infant health. Although the observed differences were small, these findings suggest that perinatal antibiotic exposure may influence early sleep regulation and highlight the need for further research into underlying mechanisms, including alterations in the infant microbiome.