The anterior cervical angle: A novel predictor of vaginal birth


Şeker E., Ümit C., Süt H., Koçar M., Sarıtaş E., AYNAOĞLU YILDIZ G.

International Journal of Gynecology and Obstetrics, vol.172, no.1, pp.639-644, 2026 (SCI-Expanded, Scopus) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 172 Issue: 1
  • Publication Date: 2026
  • Doi Number: 10.1002/ijgo.70396
  • Journal Name: International Journal of Gynecology and Obstetrics
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, CAB Abstracts, CINAHL, EMBASE, Gender Studies Database, Public Affairs Index
  • Page Numbers: pp.639-644
  • Keywords: cesarean section, delivery, Transperineal ultrasound, utero-cervical angle
  • Ankara University Affiliated: Yes

Abstract

Objective: This study investigates the role of anterior utero-cervical angle as a predictor of labor induction success, comparing outcomes between normal vaginal delivery and cesarean section groups. Methods: A prospective cohort study was conducted on 55 patients undergoing labor induction (46 normal vaginal delivery, 9 cesarean section). Parameters such as maternal age, weight, height, body mass index (BMI; calculated as weight in kilograms divided by the square of height in meters), cervical length, anterior cervical angle (ACA), Bishop score, and levator ani measurements were analyzed. Statistical significance was assessed using Fisher exact test, independent sample test, Mann–Whitney U test, or χ2 test (P < 0.05). Results: The ACA was significantly different between normal vaginal delivery (108.02 ± 22.38°) and cesarean section (86.11 ± 26.09°) groups (P = 0.026). We determined an optimal ACA threshold of 96° for the prediction of failure of progression (sensitivity: 70%, specificity: 73%). Other significant differences included maternal weight (P = 0.0033), height (P = 0.0033), BMI (P = 0.0462), primiparity (P = 0.0161), and fetal gender (P = 0.0334). However, Bishop score, cervical length, and levator ani metrics showed no significant differences. Conclusion: Although ACA differs significantly between vaginal delivery and cesarean section groups, its independent predictive value for induction success remains limited compared with factors like primiparity and BMI. Further prospective studies are needed to clarify its clinical utility.