Acute chorioamnionitis and funisitis: definition, pathologic features, and clinical significance

Area of Science:

• Obstetrics and Gynecology
• Neonatology
• Pathology

Background:

• Acute inflammatory lesions of the placenta, including chorioamnionitis, funisitis, and chorionic vasculitis, involve neutrophil infiltration.
• These lesions represent maternal (chorioamnionitis) or fetal (funisitis, chorionic vasculitis) inflammatory responses to chemotactic gradients in the amniotic cavity.

Purpose of the Study:

• To review the definition, pathogenesis, grading, staging, and clinical significance of common placental inflammatory lesions.
• To elucidate the role of intra-amniotic infection and sterile inflammation in placental pathology.

Main Methods:

• Review of existing literature on placental inflammatory lesions.
• Analysis of the mechanisms involving chemokines (e.g., interleukin-8) and danger signals in neutrophil recruitment.
• Examination of the association between placental lesions and gestational age, labor type, and membrane status.

Main Results:

• Chorioamnionitis, funisitis, and chorionic vasculitis are prevalent, particularly in preterm placentas.
• Both infectious and sterile intra-amniotic inflammation contribute to these lesions.
• Funisitis and chorionic vasculitis characterize the fetal inflammatory response syndrome, linked to preterm labor and neonatal morbidity.

Conclusions:

• Acute placental inflammation is a significant finding with implications for both maternal and fetal health.
• The fetal inflammatory response syndrome is associated with adverse neonatal outcomes, including sepsis and neurodevelopmental issues.
• Understanding these lesions is crucial for managing preterm labor and improving neonatal care.