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Abstract

Background: Preterm birth, especially when occurring before 32 weeks of gestation, is a leading cause of neonatal morbidity and mortality worldwide. Early identification of pregnancies at risk is essential for initiating timely interventions that may improve neonatal outcomes. Transvaginal ultrasound (TVUS) assessment of cervical length has gained prominence as a reliable, non-invasive method to predict spontaneous preterm birth, particularly in asymptomatic women and high-risk populations.
Objective: To systematically review and evaluate the effectiveness of cervical length measurement via TVUS in predicting the risk of spontaneous preterm birth in pregnant women.
Methods: This systematic review followed PRISMA guidelines. Electronic databases including PubMed, ResearchGate, and Google Scholar were searched for studies published between 2015 and 2025. Original research articles that evaluated cervical length using TVUS in pregnant women at risk of preterm birth were included. Studies were excluded if they were case reports, narrative reviews, or involved women with cervical cerclage, uterine anomalies, or prior cervical surgeries. A total of 15,857 records were retrieved. After applying a time filter and removing duplicates, 310 articles remained. Full-text screening was performed on 70 studies, of which 10 met the final inclusion criteria.
Results: The 10 included studies, all prospective in design, encompassed a cumulative sample of 9,401 participants. Cervical length cutoffs ranged from ≤22 mm to <40 mm, with the most common threshold being ≤25 mm. All studies consistently demonstrated a significant association between shorter cervical length and increased risk of spontaneous preterm birth. Serial measurements were found to enhance predictive accuracy.
Conclusion: TVUS-based cervical length assessment is an effective and safe method for identifying women at increased risk of spontaneous preterm birth. Its integration into prenatal care, particularly when combined with obstetric history and serial monitoring, supports timely and personalized obstetric management.