Uterocervical Angle (UCA) Combined With the Bishop Score as a Predictor for Successful Induction of Labor in Term Pregnancy: A Prospective Observational Study.

BACKGROUND: Traditionally, the Bishop score has been used to evaluate cervical maturity and predict the outcome of induction, but now uterocervical angle (UCA) and cervical length have gained attention to determine the possibility of successful induction of labor (IOL).

AIM AND OBJECTIVE: This study aimed to evaluate the accuracy of ultrasonographically measured UCA combined with the Bishop score in speculating successful IOL in term pregnancy.

METHODS: The study included 356 pregnant women presenting at term and undergoing IOL following institutional protocol. The pre-induction cervical status was evaluated using both the Bishop score and two-dimensional transvaginal sonography to measure cervical length and anterior UCA. Cervical assessment parameters, UCA, cervical length, and Bishop score, were compared between those with successful induction and failed IOL.

RESULTS AND CONCLUSION: The best cut-off value in speculating the probability of successful IOL for UCA was ≥107.25° (sensitivity of 57.3% and specificity of 72.8%) and for the Bishop score was ≥4 (sensitivity of 59.3% and specificity of 72.8%). Better performance was shown by the criteria of UCA ≥107.25° or Bishop score ≥4, with 80.6% sensitivity and 64.1% specificity in speculating successful IOL. The mean duration of the latent phase and active phase were significantly shorter in patients with wider UCA (≥107.25°) (p<0.05) who entered the active phase of labor. UCA has a significant role in speculating the probability of successful IOL.