A comparative study of clinical utility of parameters for prognostic evaluation of women with premature labor

It has been widely accepted that chorioamnionitis is one of major causes of preterm delivery. Inflammatory process in the uterine cervix and/or fetal membranes would stimulate the local tissue to produce lots of bioactive substances which are potent to bring uterine contractions and/or cervical ripening, resulting in parturition. Non-specific clinical markers of inflammation and parameters reflecting the local inflammatory changes in utero have been utilized to determine severity of the pathological state. However, there are still some cases of premature labor in which prognoses are falsely estimated. The purpose of this study was to evaluate the significance of vaginal microbial environment, concentration of oncofetal fibronectin (fFN) in vaginal pool and concentrations of IL-8 in uterine cervical mucus for predicting outcomes of gravidas with premature labor.<br>  Retrospective analysis was done for 124 patients with premature labor between 22 and 33 weeks of pregnancy. All the subjects carried singletons. They received in-patient management with appropriate drug therapy after determination of the followings: bacterial and fungal culture of vaginal secretions, concentration of oncofetal fibronectin (fFN) in vaginal pool, and that of IL-8 in cervical mucus. Correlations between each of them and outcomes of pregnancy were investigated.<br>  Numbers of cases resulting in premature delivery before 34 weeks of gestation (delivery before 34) and delivery within 7 days after admission (refractory illness) were 28 (22.6%) and 18(14.5%), respectively. Fifty cases (40.3%) were positive for vaginal bacteria other than lactobacillus and/or fungi, and showed slightly higher incidence of delivery before 34 and significantly higher rate of refractory illness compared with those of negative results. There were no differences in cervical mucus IL-8 levels between the groups. Subjects with positive for vaginal pool fFN (47/124=37.9%) showed significantly higher incidence of delivery before 34 or refractory illness than did those with negative fFN, while the former had significantly lower concentration of cervical mucus IL-8 compared with the latter. For patients with negative vaginal pool fFN, those who had any vaginal microbes other than lactobacillus or fungi had higher risk of refractory illness than did those who had lactobacillus and/or fungi. This trend was also same for pregnant women with positive vaginal pool fFN. Concentrations of IL-8 (ng/ml) ranged between 1 and 1873. Median was 87.5. More than half (51.6%) of the subjects showed the levels between 1 and 100. Cases with low concentration, determined with less than 300, were 83 (66.9%) and high cases were 41 (33.1%). There were no differences in the incidences of delivery before 34 or refractory illness between the groups.<br>   These data suggest that simultaneous assessment of vaginal microbial environment and vaginal pool fFN is important in evaluation of prognosis of pregnant women presenting premature labor, while usefulness of cervical mucus IL-8 concentration in the same purpose seems doubtful. [Adv Obstet Gynecol, 57 (1) : 1-12, 2005 (H17. 2)]<br>