The predictive role of uterocervical angle in labor outcomes: a narrative review

INTRODUCTION: Uterocervical angle (UCA) is the angle between the anterior or posterior uterine wall and the cervical canal, and it has become an unique ultrasonographic marker in the recent years. The predictive role of the UCA in spontaneous preterm births (sPTB) has been examined by numerous authors, however few data are available on UCA as predictor of labor outcome at term of pregnancy. Therefore, the purpose of this review is to evaluate the effectiveness of transvaginal ultrasound measurement of UCA at term, and its clinical implications in obstetrics' practice. EVIDENCE ACQUISITION: A literature search was conducted including all studies regarding the predictive role of ultrasonographic evaluation of the UCA on labor outcomes from 1990 to 2023. EVIDENCE SYNTHESIS: A narrative synthesis was subsequently performed dividing studies that considered posterior and anterior UCA. Five studies were included for the anterior UCA, and ten for the posterior UCA. UCA was then evaluated as predictor of prolonged latent phase and predictor of the onset and mode of delivery. CONCLUSIONS: It is likely that the combination of multiple cervical parameters, rather than UCA assessment alone, together with clinical information, can achieve higher levels of accuracy in predicting delivery outcomes. Future prospective studies are needed to define with greater certainty the role of UCA as a useful screening tool before laboring, but, until then, the use of UCA as a screening test to predict labor outcome should remain investigational.