Transvaginal Ultrasonographic Evaluation of the Uterine Cervix in the Prediction of a Successful Induction of Labor in Term Gestation

Yang, Soon Ha; Oh, Jung Mi; Roh, Cheong Rae; Chung, Jae Hyun

Abstract

OBJECTIVES
The purposes of this study were to determine the usefulness of transvaginal ultrasonographic assessment of the uterine cervix and to compare the diagnostic performance of ultrasonographic and digital examination of the cervix in predicting a successful induction of labor. STUDY DESIGN: One hundred-one singleton term pregnancies without ruptured membranes admitted for the labor induction were included in this study. Digital examination and transvaginal ultrasonography of the uterine cervix were performed at the time of admission. Cervical parameters evaluated included cervical length, presence of funneling, funnel length, and funnel width. Labor induction was underwent by prostaglandin E2 (PGE2) vaginal suppository and/or pitocin intravenous infusion. Outcome variable was a successful labor induction within 48 hours after beginning of the induction.
RESULTS
The prevalence of induction failure was 10.9% (11/101). Receiver-operator characteristic (ROC) curve and multiple logistic regression analysis indicated a significant relationship between the successful induction of labor and cervical length <3.1 cm. The diagnositic indices of endocervical length was superior to those of Bishop's cervical score in predicting a successful induction of labor. In patients with cervical length <3.1 cm, the labor was induced successfully with fewer tablets of PGE2, less use of pitocin infusion, and shorter induction-delivery interval.
CONCLUSION
Transvaginal ultrasonographical examination of the uterine cervix is more accurate than digital examination of the cervix in the prediction of a successful induction of labor in term gestation.