Predicting preterm delivery: comparison of cervicovaginal interleukin (IL)-1 beta, IL-6 and IL-8 with fetal fibronectin and cervical dilatation

Objective: To compare the cervicovaginal cytokines IL-1 beta, IL-6 and IL-8 with fetal fibronectin (fFN) and cervical dilatation in the prediction of preterm delivery. Study design: Cervicovaginal cytokine concentration and fFN status were measured in 104 women with symptoms of preterm labour and intact membranes between 24(0) and 33(6) weeks and related to delivery within 2 and 7 days, Results: A group of 18% had cervical dilatation greater than or equal to 1 cm and 18% were positive for fFN. Preterm delivery within 2 and 7 days occurred in 5 and 12%, respectively. Only IL-6 demonstrated any ability to predict delivery within 2 and 7 days (area under the ROC curve = 0.63 and 0.75, respectively). Using 35 pg/ml (75th centile) as a cut-off, IL-6 had a sensitivity and specificity of 60 and 77% for predicting delivery within 2 days, and 62 and 80% for predicting delivery within 7 days. This is similar to the performance of cervical dilatation or fFN status. Conclusions: Measurement of cervicovaginal cytokines has limited ability to predict imminent delivery apart from cervicovaginal IL-6 concentrations, which, in this population, is equivalent to that of fFN status and cervical dilatation greater than or equal to 1 cm. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.