Tomomi Kotani

Aims To predict preterm birth (PTB) accurately, we conducted a comprehensive cytokine assay using cervicovaginal fluid (CVF) and evaluated the additive effects of cytokine levels on the fetal fibronectin (fFN) test. Methods A total of 645 CVF samples were collected from 256 asymptomatic pregnant women between 24 and 35 weeks gestation, exhibiting short cervix. After selection based on specific criteria, 17 cytokines in 105 CVF samples were simultaneously measured using multiplex assay. Multivariate logistic regression analysis was performed to evaluate the association between cytokine levels and impending PTB, which is defined as PTB within 2 weeks after CVF collection. Moreover, receiver operating characteristic (ROC) analysis was performed in women with positive fFN results, which was validated using another set of 65 CVF samples. Results In positive fFN women, the CCL2 level was significantly higher in the impending PTB group than the other group ( p < 0.01) and a predictor of impending PTB (adjusted odds ratio 1.020, 95% confidence interval [95% CI] 1.003–1.038, p = 0.020). The cutoff value of CCL2 was 64.8 pg/mL (are under the curve 0.726, p = 0.004, 95% CI 0.593–0.859, sensitivity 45.2%, specificity 91.7%). Additionally, the reliable classification performance of proposed ROC model could be validated. However, measuring cytokine levels could not help in predicting impending PTB in women with negative fFN or normal labor onset in healthy‐term women. Conclusion Comprehensive analysis of CVF cytokines revealed that the CCL2 level significantly improves the prediction of impending PTB in asymptomatic fFN‐positive women with a short cervix, which may contribute to better clinical management.