Association of Chorioamnionitis with Early and Late Neonatal Sepsis in Preterm Infants with Gestational Age < 32 Weeks

Background: Chorioamnionitis (CA) is a major pathological cause of preterm labor and is associated with both short- and long-term adverse outcomes in neonates, including early-onset sepsis (EOS) and late-onset sepsis (LOS). Neonatal sepsis remains a significant contributor to morbidity and mortality in neonatal intensive care units (NICUs). Aim: This study aimed to evaluate the association between maternal chorioamnionitis and the incidence of early-onset and late-onset neonatal sepsis in preterm neonates born at <32 weeks’ gestation. Furthermore, the study investigated maternal and neonatal factors affecting the presentation of sepsis. Methods: A retrospective cohort study was conducted on the medical records of preterm neonates born between 2020 and 2022. Inclusion criteria were gestational age < 32 weeks, available microbiological or histological examination for chorioamnionitis, and complete maternal medical records. Infants were categorized into two groups based on the presence (CA group) or absence (non-CA group) of histological and/or microbial chorioamnionitis. Descriptive statistical analyses were performed, including calculation of frequencies and percentages for categorical variables and means with standard deviations and ranges for continuous variables. Results: A total of 189 neonates were included, with a mean birth weight of 1286 ± 405 g and a mean gestational age of 29.2 ± 2.1 weeks. The CA group consisted of 55 neonates (29.1%), while 134 (70.9%) were in the non-CA group. Early-onset sepsis (EOS) occurred in 23 neonates (12.2%), with a significantly higher incidence in the CA group compared to the non-CA group (21% vs. 8%, p = 0.014). Late-onset sepsis (LOS) developed in 66 neonates (34.9%), but no significant difference in incidence was observed between the two groups (p = 0.402). Parsimonious logistic regression analysis identified maternal chorioamnionitis as an independent predictor of EOS (Odds Ratio 2.07, 95% CI 1.85–5.08; p = 0.009). Conclusions: Intrauterine infection and inflammation caused by chorioamnionitis are linked to an increased risk of early-onset sepsis in neonates born before 32 weeks’ gestation. However, chorioamnionitis does not appear to significantly influence the incidence of late-onset sepsis, which appears to be more closely associated with postnatal factors.