INTRODUCTION: Chorioamnionitis can initiate fetal lung injury and result in neonatal chronic lung disease (CLD). Although neonates with CLD have higher amniotic fluid concentrations of proinflammatory cytokines, overexpression of transforming growth factor β (TGF-β) also seems to be important in the pathogenesis of neonatal CLD.
OBJECTIVE: Our goal was to investigate how TGF-β is related to fetal lung injury induced by chorioamnionitis.
METHODS: Forty-four amniotic fluid samples were obtained at delivery from preterm infants (median gestational age: 28 weeks; median birth weight: 908 g). TGF-β and interleukin 6 (IL-6) concentrations in amniotic fluid were measured with enzyme-linked immunosorbent assays.
RESULTS: TGF-β concentration in amniotic fluid correlated with IL-6 concentration (P < .0001). Both TGF-β and IL-6 concentrations in amniotic fluid increased with increasing histologic severity of chorioamnionitis (each P < .0001). Coexisting presence of neonatal CLD and histologic chorioamnionitis was associated with significantly higher amniotic fluid TGF-β and IL-6 concentrations than presence of neonatal CLD without histologic chorioamnionitis or absence of both (mean TGF-β level: 454.3 vs 119.2 vs 151.8 pg/mL [P < .0001]; mean IL-6 level: 5.14 vs 0.99 vs 1.64 ng/mL [P = .0005]). Both TGF-β and IL-6 concentrations in amniotic fluid correlated with duration of neonates' need for oxygen administration (each P < .0001).
CONCLUSIONS: Amniotic fluid TGF-β may be important in chorioamnionitis-induced fetal lung injury that results in neonatal CLD.