Respiratory Related Hospitalization in Children With Exposure to Meconium Aspiration or Staining.

Background: We investigated whether neonates exposed to meconium had a higher risk of respiratory hospitalization in childhood.

Methods: We analyzed a longitudinal cohort of 1,271,563 children with 6,334,857 person-years of follow-up between birth and age 5 years in Quebec, Canada from 2006 to 2022. The exposure was meconium aspiration or meconium staining without aspiration at birth. The outcome was hospitalization for bronchiolitis, asthma, and other allergic conditions up to age 5 years. We estimated hazard ratios (HR) and 95% confidence intervals (CI) for the association between meconium exposure and these outcomes using Cox regression models adjusted for patient characteristics. We additionally examined associations according to gestational age.

Results: A total of 6050 children had meconium aspiration (0.5%) and 131,238 were exposed to meconium without aspiration (10.3%). Compared with no exposure, meconium aspiration was associated with 1.24 times the risk of bronchiolitis (95% CI: 1.09-1.42), 1.43 times the risk of asthma (95% CI: 1.20-1.69), and 1.40 times the risk of other allergy hospitalization (95% CI: 1.11-1.76). Meconium aspiration was associated with these outcomes among children born at term (HR: 1.28, 95% CI: 1.14-1.44) and post-term (HR: 1.56, 95% CI: 1.26-1.94). There was no association for children born preterm. Meconium exposure without aspiration appeared to protect against the outcomes (HR: 0.92, 95% CI: 0.90-0.95), but the association disappeared when we accounted for gestational age.

Conclusion: Meconium aspiration is associated with a higher risk of hospitalization for respiratory or atopic complications, but meconium exposure without aspiration is not associated with these outcomes.