integration of cervical length, inflammatory marker, and vaginal biomarkers (pamg-1 and ffn) in the diagnosis of threatened preterm labor

The aim of this research was to evaluate the diagnostic efficacy of integrating cervical length (cl), interleukin-6 (il-6), placental alpha microglobulin-1 (pamg-1), and fetal fibronectin (ffn) in predicting preterm birth among pregnant women with threatened preterm labor (tpl).this study retrospectively analyzed clinical data from 150 pregnant women admitted for tpl between january 2021 and december 2024. participants were divided into two groups based on pregnancy outcome: full-term delivery (n=85) and preterm birth (n=65). additionally, 100 healthy pregnant women with no history of adverse pregnancy outcomes who underwent routine prenatal examinations during the same period were selected as the healthy control group. all participants underwent transvaginal ultrasound to measure cl, and venous blood samples were collected to assess serum il-6 levels. pamg-1 and ffn levels were measured in vaginal secretions.there were no significant differences in baseline characteristics among the three groups. however, significant differences in cl, serum il-6 levels, and positive rates of pamg-1 and ffn were detected. pearson correlation analysis showed significant associations between cl, il-6, pamg-1, ffn, and preterm birth. roc curve analysis indicated that the auc values for cl, il-6, pamg-1, and ffn alone were 0.798, 0.803, 0.753, and 0.754, respectively.the combined application of these markers yielded an auc of 0.920, significantly higher than any single marker. the combined use of cl, il-6, pamg-1, and ffn significantly enhances the diagnostic accuracy of preterm birth in patients with tpl.