RESUMEN
<p><b>OBJECTIVE</b>To explore the relationship between histological chorioamnionitis (HCA) and fetal inflammatory response syndrome (FIRS) and brain injury in preterm infants.</p><p><b>METHODS</b>One hundred and three singleton infants with premature rupture of membranes (PROM) (gestation ages of less than 34 weeks) were enrolled. All the placentas were submitted for pathological evaluation. Umbilical cord blood interleukin 6 (IL-6), interleukin 8 (IL-8), tumor necrosis factor alpha (TNF-α) and granulocyte-colony stimulating factor (G-CSF) levels were measured with liquid chip. All preterm infants accepted brain imaging examinations. Based on the placental pathological examination and umbilical cord blood level of IL-6, the 103 infants were classified into HCA⁻ FIRS⁻, HCA⁺ FIRS⁻, and HCA⁺ FIRS⁺ groups.</p><p><b>RESULTS</b>The incidences of HCA, FIRS, and brain injury were 53.4%, 20.4% and 38.8% respectively. The prevalence of brain injury in HCA⁻ FIRS⁻, HCA⁺ FIRS⁻, and HCA⁺ FIRS⁺ cases was 21%, 41%, and 76% respectively (P<0.01). The grade 2 and grade 3 of placental inflammation and the inflammation at stage 2 and stage 3 increased the risk of brain injury. The cord blood levels of IL-8, TNF-α, and G-CSF in the HCA⁺ FIRS⁺ group were significantly higher than in the other two groups, and the levels of the above parameters in the HCA⁺ FIRS⁻ were higher than in the HCA⁻ FIRS⁻ group (P<0.05).</p><p><b>CONCLUSIONS</b>Placental inflammation and FIRS are associated with brain injury in preterm infants. Preterm infants exposed to severe placental inflammation have an increased risk of brain injury. Cord blood IL-8, TNF-α and G-CSF may be involved in the process of brain injury in preterm infants with placental inflammation and FIRS.</p>