OP25.09: Sonographic measurement of cervical length in predicting intra-amniotic inflammation in women with preterm labor: a comparison with tests using maternal blood and amniotic fluid

Abstract

Objective: To evaluate cervical length and gestational age as predictors of intra-amniotic inflammation in patients admitted because of preterm labor and intact membranes. Methods: 93 pregnant women with preterm labor and intact membranes were included in our study. Transvaginal cervical length was measured on admission and transabdominal amniocentesis was performed within the first 48 hours at admission. Positive amniotic fluid cultures defined intra-amniotic infection. High levels of IL6 defined intra-amniotic inflammation. To determine the best cut off point of IL6, a ROC curve was constructed. Logistic regression was used to investigate associations of different explanatory variables with inflammatory status. Results: Intra-amniotic infection and inflammation rates were 14% and 28%, respectively. ROC curve analysis showed that best cut off value for IL6 was 13.4 ng/mL which was comparable to the cut off of 11.3 ng/mL reported previously by other authors. Cervical length < 15 mm and gestational age at admission < 28 weeks were independently associated with intra-amniotic inflammation. A strategy considering these two non-invasive parameters could detect 84% of women with intra-amniotic inflammation. Conclusion: Cervical length and gestational age at admission can be used as a non-invasive method to assess the risk of intra-amniotic inflammation in preterm labor and intact membranes. Aims: To determine whether sonographic cervical length is valuable in terms of predicting intra-amniotic inflammation in women with preterm labor and intact membranes, and to compare performance with maternal blood C-reactive protein (CRP), white blood cell (WBC), amniotic fluid (AF) culture, and WBC. Methods: Transvaginal ultrasonographic assessment of cervical length was performed and maternal blood was collected for the determination of CRP and WBC immediately after amniocentesis in 133 consecutive women with preterm labor at 22.1 to 35.0 weeks of gestation. AF obtained by amniocentesis was cultured for aerobic and anaerobic bacteria and for Mycoplasmas, and WBC count was determined. Intra-amniotic inflammation was defined as an elevated amniotic fluid interleukin-6 concentration (> 2.6 ng/mL). Univariate and multivariate analyses were used for statistical analyses. OP25.08: TableResults: The prevalence of a positive amniotic fluid culture was 8% (11/133) and that of intra-amniotic inflammation was 20% (26/133). Women with intra-amniotic inflammation had a significantly higher mean maternal blood CRP and WBC, higher rate of a positive AF culture, higher mean AF WBC count, and lower mean gestational age at amniocentesis than did those without intra-amniotic inflammation. However, the mean cervical length was not significantly different between women with and without intra-amniotic inflammation (p = 0.069). Multivariate analysis demonstrated that maternal blood CRP and AF WBC count, but not cervical length, were significantly and independently associated with intra-amniotic inflammation. Conclusions: AF WBC and maternal blood CRP...