Maternal risk score for the prediction of fetal inflammatory response syndrome after preterm premature rupture of membranes

Aim: Preterm premature rupture of membranes (PPROM) is common in preterm births. Fetal inflammatory response syndrome (FIRS) is present in nearly 50% of PPROM cases. We created a risk score to predict FIRS using maternal factors after PPROM.

Methods: We conducted a retrospective study of singleton pregnancies complicated by PPROM that resulted in delivery at 23-35 weeks of gestation. Antepartum maternal factors and umbilical cord blood interleukin-6 (IL-6) data were analyzed. FIRS was defined as IL-6 > 11 pg/mL.

Results: Umbilical cord blood IL-6 and maternal blood data within 24 h before parturition were available for 158 cases; 66 were diagnosed with FIRS (41.8%; median IL-6, 57.55 pg/mL). We created a risk score (FIRS score) comprising expected delivery weeks (≤30 weeks), maternal C-reactive protein (≥1.2 mg/dL), maternal white blood cell count (≥13 000/μL), corticosteroid use (none) and PROM latency period (≥3 days) from the multivariate logistic regression model predicting FIRS. Receiver operating characteristic curve analysis of the score produced the following results: area under the curve, 0.82; 95% CI, 0.76-0.89; cut-off value, 7.5; sensitivity, 89%; specificity, 63%; positive predictive value, 63% and negative predictive value, 89%. The probability of FIRS according to the categories of the FIRS score was 11% for those with a score of 0-7, 50% for a score of 8-15, and 88% for a score of 16-22.

Conclusion: The devised maternal risk score could predict FIRS and be helpful to decide the delivery timing for the cases of PPROM.