Chorioamnionitis and Neonatal Morbidity and Mortality in Extremely Preterm Infants Born at 23–28 Weeks: A Single-Centre Retrospective Study

Background/Objectives: Chorioamnionitis (CA), an inflammation, with or without infection, involving the amniotic fluid, placenta, fetal membranes or decidua, can significantly impact fetal and neonatal development. This study aimed to determine the prevalence of chorioamnionitis and confirm its correlation with neonatal morbidity and mortality, in a single tertiary center. Methods: This observational, retrospective study was conducted over three years (2019–2021) in a tertiary neonatal intensive care unit, examining 80 preterm infants born at 23–28 weeks of gestation. Spearman rank correlation, χ2 tests, and multivariate logistic regression were used to assess associations between chorioamnionitis exposure and neonatal outcomes. Results: Among the 80 newborns analysed, clinical chorioamnionitis was identified in 12 preterm infants, while 65 (81.3%) presented histological chorioamnionitis. No significant association was found between histological chorioamnionitis stage and gestational age at birth (Spearman ρ = −0.15, p = 0.195). Premature rupture of membranes was significantly more frequent in the CA-exposed group (46.2% vs. 13.3%, p = 0.019). In unadjusted analyses, histological chorioamnionitis exposure was associated with higher rates of adverse neonatal outcomes, including early-onset sepsis (46.2% vs. 26.7%), intraventricular haemorrhage (73.8% vs. 60.0%), bronchopulmonary dysplasia (15.9% vs. 6.7%), and retinopathy of prematurity (11.3% vs. 0.0%); however, most of these differences did not reach statistical significance. After multivariate adjustment, histological chorioamnionitis remained independently associated with severe respiratory distress syndrome (adjusted OR 25.84, 95% CI 2.49–268.44, p = 0.006). Mortality was numerically lower in the CA-exposed group (27.7% vs. 46.7%); however, this difference did not reach statistical significance (p = 0.216). Conclusions: Histological chorioamnionitis was independently associated with severe respiratory distress syndrome. Associations with early onset sepsis, bronchopulmonary dysplasia, and retinopathy of prematurity were observed in unadjusted analyses but were not independently significant after adjustment for perinatal confounders. No significant association was found between chorioamnionitis and neonatal mortality. While clinical diagnostic criteria for chorioamnionitis demonstrated good specificity, their poor sensitivity underscores the urgent need for improved diagnostic tools, including routine histological examination of the placenta.