BACKGROUND: Preterm birth remains a leading cause of neonatal morbidity and mortality worldwide. Cervical length (CL) measured by transvaginal ultrasound is an established predictor, but single-timepoint measurements have limited accuracy, particularly in nulliparous women without prior obstetric history. This study evaluated whether dynamic monitoring of CL combined with cervical index (CI) improves preterm birth prediction in nulliparous women. METHODS: This retrospective cohort study included 644 nulliparous women with singleton pregnancies who underwent serial transvaginal ultrasound cervical assessments at three timepoints: T1 (16-20 weeks), T2 (20-24 weeks), and T3 (24-28 weeks). CL, CI (calculated as funnel length + 1/CL), and rate of cervical change (ΔCL rate) were measured. Multivariable logistic regression identified independent predictors. Prediction models were compared using area under the receiver operating characteristic curve (AUC), and a nomogram was developed for clinical application. RESULTS: = 0.394) and clinical utility on decision curve analysis. CONCLUSIONS: Dynamic monitoring of cervical parameters significantly enhances preterm birth prediction in nulliparous women compared to single-timepoint assessment. The combined model incorporating CL, CI, and rate of change provides excellent discrimination and may facilitate targeted preventive interventions. External validation in multicenter cohorts is warranted.
Wen-jun et al. (Fri,) studied this question.