Meconium Aspiration Syndrome and the Association with Preschool Asthma.

Abstract

Meconium aspiration syndrome (MAS) is an acute neonatal respiratory disorder resulting from aspiration of meconium-stained amniotic fluid, leading to airway obstruction, inflammation, and hypoxemia. Although its perinatal presentation is well described, the long-term association with asthma remains unknown. Does MAS associate with subsequent development of preschool asthma? A retrospective cohort study was conducted using national database, which included infants born between 2010 and 2024 with continuous follow-up until the age of six. Each MAS case was matched 1:4 to controls without MAS using Mahalanobis distance matching. The primary outcome was asthma, defined by the Asthma Integrated Diagnosis Index (AIDI), a specific composite measure. Secondary outcomes included individual asthma-related diagnoses and medication use. Kaplan-Meier analysis was performed to evaluate time to outcome, accounting for the age at which events occurred. Among 326,940 eligible children, 730 (0.2%) were diagnosed with MAS. Post-matching, MAS was associated with 64% higher proportion of asthma up to six years of age (95%CI=1.29-2.06; P<0.001). Other long-term respiratory morbidities, such as bronchiolitis and obstructive sleep apnea, were also more frequent among MAS survivors. Atopic conditions, including dermatitis, rhinitis, and food allergies, did not differ significantly between groups. Sensitivity analysis using Inverse Probability of Treatment Weighting (IPTW) supported these findings. MAS was associated with increased risks of asthma and bronchiolitis in early childhood. These findings suggest that neonatal lung injury from MAS may impair airway development, contributing to asthma inception.