Diagnostic value of Chorioquick for detecting chorioamnionitis in women with premature rupture of membranes

Abstract

Objective: To determine the accuracy of a semi-quantitative interleukin-6 (IL-6) vaginal secretion rapid test (Chorioquick) for detecting chorioamnionitis in women with premature rupture of membranes (PROM). Methods: A prospective cohort study in five tertiary hospitals in Nigeria involved women with confirmed PROM at term and preterm PROM with or without suspected chorioamnionitis from August 1, 2017, to October 31, 2018. Cervicovaginal fluid samples were tested for chorioamnionitis using the Chorioquick test. Samples were repeated at decision to deliver. The test was considered positive if at least the indicator ‘IL-6 low’ of the three Chorioquick biomarkers (low, medium, high) was positive, or negative if none of the biomarkers were positive. Chorioamnionitis was histologically confirmed post-delivery using three tissue samples. Primary outcome measures were sensitivity, specificity, and accuracy. Results: Of 73 women, on histological confirmation, 39 were true positive and 29 were true negative (for chorioamnionitis) to the Chorioquick test at repeat assessment. Overall, the Chorioquick test had a sensitivity of 97.5% (95% confidence interval [CI] 85.3–99.9), specificity 87.9% (70.9–96.0), and accuracy 93.2% (79.5–99.1). Sub-group analysis of women <37 weeks of pregnancy showed a sensitivity of 100.0% (95% CI 83.4–100.0), specificity of 91.3% (70.5–98.5), and accuracy of 95.8% (82.5–99.5). Triple positive samples were 100.0% specific in all gestations. Conclusion: Chorioquick showed favorable utility for detecting chorioamnionitis in PROM and could be a reliable, non-invasive rapid tool in a real-world clinical setting.