Usefulness of cervical volume by three-dimensional ultrasound in identifying the risk for preterm birth.

This study was conducted to establish the relationship between three-dimensional (3-D) cervical volume and the risk of spontaneous preterm birth. A total of 391 asymptomatic women with singleton pregnancies were prospectively evaluated two-dimensional cervical length and 3-D cervical volume at 20-24 weeks of gestation. We assessed the relationship between cervical factors and the risk for preterm birth before 36 weeks of gestation. Logistic regression analysis demonstrated that not only cervical length (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.88-0.99, p = 0.002), but also cervical volume (OR, 0.26; 95% CI, 0.11-0.61, p = 0.045) was independent predictor of preterm birth. A combined approach in which a gravida was regarded as positive with a short cervical length (≤28 mm) or a small cervical volume (≤20 cm(3)) had a sensitivity of 57.1% for preterm birth. Screening combining cervical length and volume may provide a better prediction of preterm birth.