Evidence of both foetal inflammation and hypoxia-ischaemia is associated with meconium aspiration syndrome.

Foetal hypoxia–ischaemia is a key trigger of meconium aspiration syndrome (MAS). However, many neonates develop MAS without evidence of hypoxia–ischaemia, suggesting the presence of covert but important risk variables. We evaluated the association of MAS with clinical variables, placental histopathologic findings, and inflammatory biomarkers at birth. Of 1336 symptomatic and asymptomatic term singleton neonates with meconium-stained amniotic fluid, 88 neonates (6.6%) developed MAS. Univariate analysis showed that MAS development was associated with low 1- and 5-min Apgar scores, low cord blood pH, funisitis, higher α1-acid glycoprotein levels, and higher haptoglobin levels (all p < 0.001 except for p = 0.001 for haptoglobin). Associations of MAS with caesarean delivery (p = 0.004), premature rupture of the membranes (p = 0.006), chorioamnionitis (p = 0.007), and higher C-reactive protein levels (p = 0.008) were lost when adjusted for multiple comparisons. The final multivariate model to explain MAS development comprised lower cord blood pH (odds ratio [OR] 0.58; 95% confidence interval [CI] 0.47–0.73; p < 0.001), funisitis (OR 2.45; 95% Cl 1.41–4.26; p = 0.002), and higher α1-acid glycoprotein levels (OR 1.02; 95% Cl 1.01–1.03; p = 0.001). Our data from a large cohort of neonates suggested that intrauterine inflammation is one of the key independent variables of MAS development, together with foetal hypoxia–ischaemia.