THE DIAGNOSTIC-VALUE OF INTERLEUKIN-8 AND FETAL FIBRONECTIN CONCENTRATIONS IN CERVICAL SECRETIONS IN PATIENTS WITH PRETERM LABOR AND INTACTMEMBRANES

The objectives of this study were 1) to evaluate interleukin-8 concent rations in cervical secretions in predicting preterm delivery, microbi al invasion of the amniotic cavity and histologic chorioamnionitis in patients with preterm labor and intact membranes and 2) to compare the diagnostic value of interleukin-8 with fetal fibronectin determinatio ns in predicting preterm delivery, microbial invasion of the amniotic cavity and histologic chorioamnionitis in patients with preterm labor and intact membranes. Interleukin-8 and fetal fibronectin were assayed in cervical secretions in 106 patients with singleton pregnancies and intact membranes admitted for preterm labor. Amniotic fluid obtained by amniocentesis was cultured and placentas (No = 43) analyzed for the presence of chorioamnionitis. The prevalence of pregnancies delivered preterm was 46.2% (49/106) and 15.09% (16/106) of amniotic fluid cult ures were positive. Interleukin-8 levels in cervical secretions were s ignificantly increased in patients who delivered preterm (p less than or equal to 0.0001), in presence of positive amniotic fluid culture (p = 0.0016) and histological chorioamnionitis (p = 0.008) than in patie nts with negative findings. Receiver-operator characteristics curve an alysis showed that an interleukin-8 value > 450 pg/ml is comparable to that of a fetal fibronectin value > 50 ng/ml in predicting preterm de livery (p = 0.247). Among patients who delivered preterm interleukin-8 concentrations > 860 pg/ml predicted a positive amniotic fluid cultur e with a sensitivity of 81.2% and a specificity 66.6%. Further, in pat ients who delivered preterm and had a negative amniotic fluid culture, IL-8 concentrations > 480 pg/ml predicted histological chorioamnionit is with a sensitivity 78.5% and specificity 61.5%. A positive fetal fi bronectin > 50 ng/ml was not predictive of either a positive amniotic fluid culture or the presence of histological chorioamnionitis. In con clusion, increased concentrations of interleukin-8 and fetal fibronect in are associated with impending delivery and their diagnostic value s eems comparable. However, interleukin-8 concentrations identify patien ts at risk of a positive amniotic fluid culture and the presence of hi stological chorioamnionitis. Measurement of interleukin-8 in cervical secretion is a non-invasive method to identify patients at risk for bo th preterm delivery and intrauterine infection.