Funisitis is associated with adverse neonatal outcome in low-risk unselected deliveries at or near term

This study aimed to determine the incidence and clinical outcomes for varying patterns of placental histological inflammation (consistent with fetal or maternal inflammatory response) in an unselected population of >1000 women with a singleton pregnancy resulting in live birth delivering at or near term. One thousand one hundred nineteen cases were studied in a blind, prospective, unselected study with placentas categorized into five histological subgroups reflecting underlying maternal or fetal inflammatory response. Clinical outcomes studied included interventional delivery, an Apgar score <7 at 1 min, neonatal acidosis (pH < 7.2) and admission to neonatal special care. One hundred eighty-eight placentas (17 %) showed histological evidence of acute inflammation: 64 with funisitis (with or without other inflammation; 6 %); 16 with extensive acute inflammation across the chorionic plate, free membranes and subchorionic fibrin (1 %); 28 with acute inflammation restricted to the chorionic plate (2 %); 12 with acute inflammation restricted to the free membranes (1 %) and 68 with acute inflammation restricted to the subchorionic fibrin (6 %). Features of extensive acute inflammation were significantly associated with increased rate of interventional delivery (assisted vaginal delivery or emergency caesarean section; P < 0.01). The presence of funisitis was significantly associated with interventional delivery and other adverse outcomes including an Apgar score <7 at 1 min, clinical evidence of sepsis and admission to the neonatal intensive care unit (P < 0.05 for all). The data represent a quantitative rather than purely qualitative analysis of the contribution of histological lesions related to inflammation on short-term adverse neonatal outcomes and interventional delivery. Funisitis and extensive inflammation are associated with adverse clinical outcomes, but the precise mechanism underlying these remains to be elucidated.