Aim: To evaluate the clinical usefulness of maternal serum interleukin-6 for the detection of subclinical chorioamnionitis and in the prediction of the latency period in patients with preterm premature rupture of membrane (PPROM).
Methods: The study group included 60 patients at 24-34 weeks of gestation complaining of PPROM. Laboratory investigations included serial measurements of IL-6, TLC and CRP. Conservative management was carried out till 36 weeks unless delivery was indicated beforehand. The main outcome measures were the latency period and the occurrence of subclinical chorioamnionitis.
Results: The mean gestational age at presentation was 30.9 weeks and 35.2 weeks at delivery. The mean IL-6 level at presentation was 4.7 pg/ml. There was no correlation between IL-6 at presentation and the latency period. In addition, those diagnosed as having subclinical chorioamnionitis by placental histopathology had significantly higher levels of IL-6 at delivery. Taking IL-6 level cutoff point of 8.5 pg/ml, histological chorioamnionitis, RDS and NICU admission were significantly higher above that level while neonatal birth weight, Apgar scores at one and five minutes were significantly lower.
Conclusion: Maternal serum IL-6 at the time of PPROM has no correlation to the latency period while IL-6 levels at the time of delivery have significant correlation to the subclinical chorioamnionitis and neonatal outcome measures.
Keywords: C-reactive protein; interleukin-6; placental histopathology; preterm premature rupture of membranes; subclinical chorioamnionitis; total leucocytic count.