Relationship between fetal inflammatory response syndrome and stages of acute placental inflammation stratified by the presence or absence of preterm premature rupture of membranes.

INTRODUCTION

Fetal inflammatory response syndrome (FIRS) is a critical condition associated with increased neonatal morbidity and mortality, regardless of gestational age at birth. This study aimed to determine the frequency of FIRS at each stage of acute placental inflammation, stratified by the presence or absence of preterm premature rupture of membranes (PPROM).

METHODS

This study included singleton pregnant women with spontaneous preterm births. Fetal inflammatory response syndrome was defined as an umbilical cord vein interleukin-6 concentration of >11.0 pg/mL. Stages of acute placental inflammation were categorized into maternal inflammatory response (MIR) and fetal inflammatory response (FIR), as defined by the Amsterdam Placental Workshop Group Consensus Statement.

RESULTS

In total, 584 pregnant women (300 with PPROM and 284 without PPROM) met the inclusion criteria. Predictive ability of the MIR stage for FIRS was higher than that of the FIR stage, with area under the receiver operating characteristic curve values of 0.85 and 0.80, respectively (P = 0.05). Frequencies of FIRS in patients with PPROM were 5 %, 64 %, 75 %, and 71 % for no MIR and MIR stages 1, 2, and 3, respectively; in patients without PPROM, the frequencies were 7 %, 26 %, 40 %, and 81 %, respectively. The frequency of FIRS was significantly higher in patients with PPROM than that in those without PPROM at MIR stages 1 and 2 (18/28 vs. 6/23, P = 0.01; 18/24 vs. 6/15, P = 0.04).

DISCUSSION: These results demonstrate the importance of considering both MIR stage and the presence or absence of PPROM when predicting FIRS based on placental pathology.