Related Experiment Video
Updated: Jul 29, 2026
External Cephalic Version: Is it an Effective and Safe Procedure?
Published on: June 6, 2020
Second-trimester cervical length and outcomes of induction of labor at term
Rupsa C Boelig1, Anju Suhag2, Juliana Guarente3
1a Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology , Sidney Kimmel Medical College of Thomas Jefferson University , Philadelphia , PA , USA.
Objective:
To evaluate whether second-trimester cervical length (CL) is associated with induction of labor (IOL) outcomes.
Methods:
Retrospective cohort study of nulliparous singletons undergoing CL screening at 18 0/7-23 6/7 weeks from 1/1/2012 to 12/31/2013. Women induced at term (≥37 weeks) were included. Primary outcome was vaginal delivery (VD) within 24 h. The effect of CL on outcomes was assessed by incidence across CL quartiles and a receiver operating characteristics (ROC) curve. Odds ratios (OR) were adjusted (aOR) for confounders.
Results:
Two-hundred-and-sixty-eight women were included. Aside from a difference in incidence of prior cervical surgery between CL quartiles (p <. 02), other characteristics were similar. Ninety-two women (35%) had a VD within 24 h (versus a CD or VD >24 h). A longer a CL was associated with a decreased likelihood of a VD within 24 h with aORs of the third and fourth quartiles of 0.35 (0.16-0.75) and 0.43 (0.21-0.90), respectively, compared to the first quartile. A CL >40 mm was predictive of not having a VD within 24 h with a sensitivity of 56%, specificity of 58% and a positive predictive value of 72%.
Conclusion:
A second-trimester CL >40 mm is associated with a decreased likelihood of VD within 24 h in an IOL.
