The predictive nature of uterocervical angles in the termination of second trimester pregnancy

To establish how useful and the predictive capacity of uterocervical angles (UCA) in the termination of second trimester pregnancies.

This prospective cohort study was conducted at a tertiary center with a total of 120 singleton pregnancies delivered between 14 and 24 gestational weeks. Before the beginning of misoprostol induction, patients were screened for both cervical length (CL) and uterocervical angles (UCA). The UCA is defined as an angle constructed by the measurement of the cervical canal and lower uterine segment. The study population was subdivided into four groups; successful and failed terminations at the end of 24 hours of induction and successful and failed terminations at the end of 48 hours of induction. We decided to further evaluate our study population based on their UCAs, and placed them into four categories; UCA ≥95°, UCA <95°, UCA ≥105°, and UCA <105°.

In the 24-hour time frame group, the mean UCA was 105.50 ± 15.38 degrees in the successful termination group and was 100.22 ± 11.12 degrees in the failed group (p = .001). In the 48-hour time frame group, the mean UCA was 104.19 ± 13.51° in the successful termination group and was 93.52 ± 7.84° in the failed group (p = .007). The mean hour of induction was shortest in the UCA ≥105° group.

Regardless of the time frames, patients who had successful terminations had a broader angle, less amount of misoprostol use and shorter duration of induction as compared to the failed termination groups. What do the results of this study add? The uterocervical angle has never been measured in second trimester pregnancies to predict the timing of termination. Our study demonstrated the useful application of this ultrasonographic finding in the prediction of successful second trimester terminations.