Estimation of Mid-trimester Transvaginal Cervical Length and Its Implications as Predictor of Preterm Birth: A Prospective Observational Study

Abstract

Objective: The length of the cervix in mid-pregnancy relates to the chance of preterm delivery; and preterm labor and birth cause a major burden to society in view of high perinatal morbidities and mortality with long-term implications. With this background, we aim to measure the implications of cervical length (CL) in mid-trimester for predicting preterm birth. Materials and Methods: A prospective observational study was conducted to compare the CL measurement at 18–22 weeks of gestation, to correlate the measurements with gestational age at delivery, and to compare the predictive value of the same for preterm delivery over 18 months on 100 cases. Results: The mean CL was 38.4 ± 9.1 (22.6–54.4) mm. No significant association of transvaginal CL was found with age. Most patients experienced term vaginal birth with significant association of CL was found with pregnancy outcome. Among preterm deliveries, the CL was shorter, but no significant association of CL was found with the type of delivery. Moreover, optimum cutoff CL (35.55 mm) had very high predictive values with a sensitivity of 100%, specificity of 62.8%, and diagnostic accuracy of 65.0%. Conclusion: Our study has added more evidence that shorter CL at 18–22 weeks of gestation was a direct predictor of spontaneous preterm birth and risky outcomes of pregnancy.

Keywords

• cervical length
• mid-trimester pregnancy
• preterm birth
• spontaneous delivery
• transvaginal sonography