Histopathological Insights into Placental Infections and Neonatal Morbidity: Systematic Review and Meta-Analysis

Abstract

Placental infections and their histopathological manifestations remain important determinants of adverse neonatal outcomes. Lesions such as acute chorioamnionitis, funisitis, villitis, and intervillositis represent maternal and fetal immune responses that may compromise fetal growth and predispose to morbidity. While several cohort and case–control studies have investigated these associations, pooled evidence quantifying their impact is limited. This systematic review and meta-analysis synthesized available data to clarify the relationship between placental infection-related lesions and neonatal morbidity. A total of 42 studies, encompassing 27,486 pregnancies, were included. Acute chorioamnionitis was associated with early-onset neonatal sepsis (OR 2.45, 95% CI 1.89–3.18) and NICU admission (OR 1.82, 95% CI 1.45–2.28). Funisitis demonstrated a stronger association with sepsis (OR 3.67, 95% CI 2.74–4.92) and severe morbidity (OR 2.91, 95% CI 2.08–4.08). Chronic villitis correlated with low birth weight (RR 1.54, 95% CI 1.21–1.95) and fetal growth restriction (RR 1.72, 95% CI 1.30–2.28). Intervillositis and massive perivillous fibrin deposition were linked with perinatal death (RR 2.68, 95% CI 1.64–4.39). Evidence certainty was moderate for funisitis and neonatal sepsis, but low for villitis and intervillositis. These findings highlight the prognostic role of placental histopathology in neonatal outcomes and the need for standardized diagnostic criteria.