Fetal inflammatory response syndrome (FIRS) and outcome of preterm neonates - a prospective analytical study

To estimate the incidence of fetal inflammatory response syndrome (FIRS) in preterm neonates and correlate it with immediate and one-year neurodevelopmental outcome.

This prospective observational analytical study, in preterm neonates with gestational age between 26 and 34 weeks was conducted from May 2014 to December 2015 in a tertiary care hospital in South India. FIRS was defined as the presence of either elevated levels of interleukin-6 (IL-6) in cord blood ≥11 pg/ml and/or the placental histopathology showing evidence of fetal inflammatory response. One hundred and twenty neonates were recruited. During delivery 2 ml cord blood for interleukin-6 and placenta were collected and stored appropriately. Based on presence/absence of FIRS (IL-6 in cord blood ≥11 pg/ml and or features of placental fetal inflammation), neonates were grouped into two groups. The neonatal and maternal characteristics between two groups were compared. The short-term outcome parameters during NICU stay and neurodevelopmental outcome at one year of corrected age was compared between groups.

Among the 120 infants studied, 19 expired. Out of 101 babies discharged, 87 were followed up till corrected 1 year of age. On examination of placenta and cord blood, 50 neonates had evidence of FIRS (41.6%). So there were 50 neonates in FIRS and 70 in NO-FIRS group. The mean gestational age, birth weight, and gender distribution were comparable between the two groups. Mortality [OR: 2.44 (CI: 1.14-5.26)] and early hypotension [OR: 2.13 (CI: 1.1-4.2)] were significantly higher in the FIRS group. The neurodevelopmental assessment at corrected age of 1 year showed that infants with FIRS had lower mean motor developmental quotient by developmental assessment scale for Indian infants (DASII) [87.6 ± 9.15 versus 93.07 ± 9.3, p < .04].

FIRS has a significant role on survival and neurodevelopmental outcome of preterm infants.