The uterocervical angle and its relationship with preterm birth.

Objectives: The objective of this study is to determine whether the uterocervical angle (UCA) correlates with the risk of spontaneous preterm birth (sPTB) < 34 weeks and assess its interobserver variability.

Study Design: Case-control study of 275 women including 34 who started labor spontaneously and gave birth before 34 weeks of gestation (preterm group) and 241 who gave birth at term (control group). Images used to report cervical length were re-measured for UCA.