Histologic chorioamnionitis, fetal involvement, and antenatal steroids: effects on neonatal outcome in preterm infants.

OBJECTIVE: The objective of the study was to study the effects of histologic chorioamnionitis (HC) with or without fetal involvement and antenatal steroid (AS) exposure on neonatal outcome in a prospective cohort of preterm infants.

STUDY DESIGN: The clinical characteristics and placental histology were prospectively collected in 301 infants born at a gestational age 32.0 weeks or less in the Erasmus University Medical Center.

RESULTS: In univariable analyses, HC without fetal involvement (n=53) was associated with decreased severe respiratory distress syndrome (RDS) (11% vs 28%; P<.05), whereas HC with fetal involvement infants (n=68) had more necrotizing enterocolitis (9% vs 2%; P<.05), intraventricular hemorrhage (IVH) (25% vs 12%; P<.05), and neonatal mortality (19% vs 9%; P<.05). In HC without fetal involvement infants, AS reduced the incidences of RDS (43% vs 85%; P<.05) and IVH (5% vs 39%; P<.01). In multivariable analyses, HC without fetal involvement was associated with decreased severe RDS (odds ratio, 0.22; 95% confidence interval, 0.05-0.93; P<.05) and increased early-onset sepsis (odds ratio, 2.22; 95% confidence interval, 1.02-4.83; P<.05).

CONCLUSION: In a prospective cohort of preterm infants, multivariable analyses reveal only a modest association between histologic chorioamnionitis and neonatal outcome.