Histological chorioamnionitis and its impact on respiratory outcome in very-low-birth-weight preterm infants

Background

The role of intrauterine infection in the development of neonatal pulmonary disease is unclear and the impact of histological chorioamnionitis (HCAM) on respiratory outcomes in preterm infants remains controversial. The aim of this study was to explore the association between HCAM and neonatal respiratory outcomes in very-low-birth-weight (VLBW) preterm infants and evaluate the stepwise difference in the stage and severity of HCAM among neonatal respiratory outcomes.

Methods

We retrospectively enrolled 129 VLBW preterm infants with placenta histopathology examinations in this study. HCAM was subdivided into 3 stages (early, intermediate, and advanced) according to the progression of the maternal inflammatory response. The perinatal characteristics, placental histopathology, and neonatal morbidities, including respiratory outcomes (respiratory distress syndrome (RDS), Wilson-Mikity syndrome (WMS) and bronchopulmonary dysplasia (BPD)), were collected for comparison.

Results

A total of 52.7% (68/129) of the infants had HCAM, including 23 early (stage 1), 30 intermediate (stage 2), and 15 advanced (stage 3) stage. There was no significant difference in the gestational age, birth body weight or mortality rate between the HCAM and non-HCAM groups. Mothers with HCAM had a significantly lower incidence of pre-eclampsia but a higher rate of premature rupture of membrane. They also had higher WBC counts and C-reactive protein levels before delivery. Neonates with HCAM had a lower incidence of RDS but were at a higher risk for developing WMS and BPD. After multivariate analysis adjustment, HCAM was still negatively associated with RDS (aOR = .069, p < .001) but without correlation with BPD. However, neonates with intermediate to advanced-stage HCAM had a higher risk of developing WMS and increased home oxygen usage rate compared to those with early-stage HCAM.

Conclusion

HCAM has a protective effect from RDS in preterm neonates. Additionally, VLBW neonates with intermediate to advanced-stage HCAM are at risk for WMS.