A prospective study to correlate the cervical length by transvaginal ultrasound with preterm labor and perinatal outcomes

BACKGROUND

This study aimed to investigate the role of transvaginal ultrasound as a screening tool to assess cervical length and improve perinatal outcomes to prevent preterm labor through appropriate interventions.

OBJECTIVE

This study aimed to determine the mean cervical length at 11 to 14 and 18 to 22 weeks of gestation and to estimate the rate of cervical length shortening and its correlation with birth outcomes.

STUDY DESIGN

This prospective study was conducted at Lady Goschen Hospital and KMC Hospital, Attavar, both of which are affiliated with Manipal Academy of Higher Education. This study included 93 pregnant women who came for antenatal care at Lady Goschen Hospital and KMC Hospital, Attavar, from December 2022 to August 2024. All participants provided consent to participate in the study. The formula is a follows: n = Zα2 (Sn)(1-Sn) / L2 × p, where Zα = 1.96 at a 95% confidence level, Sn = sensitivity, l = allowable error, and p = negative prevalence (Sn = 75% [reference article], L = 20% [80% power], and p = 50% (assumption) with 95% confidence interval and 80% power with respect to reference [prediction of preterm labor by cervical length]). Convenient sampling was performed. Data analysis was performed using descriptive statistics. Changes in follow-up were estimated using analysis of variance and the Bonferroni t test. Sensitivity, specificity, positive predictive value, and negative predictive value were estimated. Statistical analysis was performed using SPSS (version. 2.0; IBM, Armonk, New York). A P value of >.05 was considered statistically significant.

RESULTS

Cervical length measured using transvaginal ultrasound at 18 to 22 weeks of gestation was found to be more sensitive and to have better positive predictive value in predicting preterm labor than cervical length measured at 11 to 13 weeks of gestation. Cervical length between 18 and 22 weeks of gestation and the reduction of cervical length were found to be statistically significant in predicting preterm labor (P=.001).

CONCLUSION

Transvaginal ultrasound is a noninvasive and comparatively affordable modality for identifying women at risk of preterm labor. In addition, this technology could help identify women at risk of preterm labor, thereby reducing morbidity and mortality.