Comprehensive assessment of placental inflammation: Novel approach in predicting retinopathy of prematurity

The purpose of this study was to determine the independent association between placental inflammation and the development of retinopathy of prematurity (ROP). This retrospective cohort study included 591 neonates born with a gestational age (GA) ≤32 weeks and/or a birthweight (BW) ≤1500 g. Clinical data were retrospectively collected, and placentas were reexamined for acute (e.g. chorioamnionitis and funisitis) and chronic placental inflammation (e.g. chorioamnionitis, villitis of unknown etiology and chronic deciduitis). Severe acute chorioamnionitis was defined as the presence of confluent polymorphonuclear leukocytes or subchorionic microabscesses. Outcomes explored were GA, BW, small for gestational age (SGA), mechanical ventilation duration, postnatal corticosteroids, sepsis, necrotizing enterocolitis, and ROP. Acute histological chorioamnionitis and funisitis were associated with lower GA, lower SGA rates, increased duration of mechanical ventilation and increased ROP rates, while chronic chorioamnionitis and villitis were associated with higher GA and increased SGA rates. BW was significantly lower in neonates with chronic deciduitis. Subanalysis of placentas without maternal and fetal vascular malperfusion also showed increased rates of severe acute chorioamnionitis (42 % vs. 21 %), funisitis (61 % vs. 35 %) in neonates with ROP. Multivariable regression analysis revealed two placental inflammatory factors to be independently associated with ROP: severe acute chorioamnionitis (OR 2.1; 95 % CI 1.1–3.8) and funisitis (OR 1.7; 95 % CI 1.0–2.9). Structured placental evaluation of the presence of severe acute chorioamnionitis and funisitis is valuable in predicting the development of ROP. This increased risk of ROP development could be integrated into the neonatal treatment approach of high-risk neonates in a very early stage in order to reduce ROP.