Antenatal cervical length measurement as a predictor of successful vaginal birth

Antenatal cervical length measurement has paramount importance in the prediction of labor. It was compared to the Bishop Score and incorporated in the modified Bishop score due to its relevance and convenience. It is a more accurate tool that imposes no harm or distress to the patients. The study aimed to evaluate the role of antenatal cervical length measurement in the prediction of a successful vaginal birth and its relation to the duration of labor.

This was a prospective cohort study, conducted at the emergency ward of obstetrics and gynecology department. We recruited 162 women over 1 year from January 2018 to January 2019. Women eligible for the study had a transvaginal ultrasound for the examination of the cervical length before the onset of labor. The success of vaginal delivery was evaluated.

The mean cervical length (mm) was 43.3 ± 8.0. The majority of the patients labored spontaneously [102 (63.0%)] while the remaining ones required induction of labor due to different causes. One hundred and eight patients (66.7%) had a successful vaginal delivery. The cervical length was significantly shorter among patients who delivered vaginally than those delivered by CS (P-value < 0.001). Multiple factors had a significant role in the prediction of the mode of delivery (cervical length, BMI, the onset of labor, parity). Maternal body mass index and labor induction were associated with a prolonged duration of the active phase of labor.

Antenatal cervical length measurement predicted the mode of delivery as well as the gestational age at which delivery ensued. It can be used in patients' counseling regarding the mode of delivery.