Pre-induction cervical assessment using transvaginal ultrasound versus Bishops cervical scoring as predictors of successful induction of labour in term pregnancies: A hospital-based comparative clinical trial

• Published in: PloS one Vol. 17; no. 1; p. e0262387
• Main Authors: Abdullah, Zainab Hananah Abang, Chew, Kah Teik, Velayudham, V Ramesh V, Yahaya, Zainab, Jamil, Amilia Afzan Mohd, Abu, Muhammad Azrai, Ghani, Nur Azurah Abdul, Ismail, Nor Azlin Mohamed
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 26.01.2022; Public Library of Science (PLoS)
• Subjects: Adult; Biology and Life Sciences; Biopsy; Body mass; Body mass index; Body size; Cervix; Cervix uteri; Cervix Uteri - diagnostic imaging; Cesarean section; Childbirth & labor; Clinical trials; Delivery, Obstetric - methods; Evaluation; Female; Gestational age; Gynecology; Health aspects; Humans; Induced labor; Labor, Induced (Obstetrics); Labor, Induced - methods; Malaysia; Medical research; Medicine and Health Sciences; Methods; Minority & ethnic groups; Obstetrics; Pain; Patients; Physical Sciences; Physiological aspects; Pregnancy; Pregnancy Outcome; Pregnancy Trimester, Third; Pregnant women; Regression analysis; Research and Analysis Methods; Statistical analysis; Success; Term Birth; Tertiary; Transvaginal ultrasonography; Ultrasonic imaging; Ultrasonography, Prenatal; Ultrasound; Vagina; Malaysia; Selangor Malaysia
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0262387

To evaluate the association between transvaginal ultrasound scan of cervix and Bishop's score in predicting successful induction of labour, cut-off points and patients' tolerability and acceptance for both procedures. A comparative clinical trial. A tertiary hospital in Selangor, Malaysia. 294 women planned for elective induction of labour for various indications were included. All women had transvaginal ultrasound to assess the cervical length and digital vaginal examination to assess the Bishop cervical scoring by separate investigators before induction of labour. To evaluate the association of the cervical length by transvaginal ultrasound scan and Bishop score in predicting successful induction of labour. Variables associated with successful induction of labour and patients' tolerability and acceptance for transvaginal ultrasound scan of cervix. There was no statistically significant difference among the vaginal and Caesarean delivery groups in terms of mean maternal age, height, weight, body mass index, ethnicity and gestational age at induction. Vaginal delivery occurred in 207 women (70.4%) and 87 women (29.6%) delivered via Caesarean section. There was a high degree of correlation between the cervical length and Bishop score (r-value 0.745; p <0.001). Sonographic assessment of cervical length demonstrated a comparable accuracy in comparison to Bishop score. Analysis using ROC curves noted an optimal cut-off value of ≤27mm for cervical length and Bishop score of ≥ 4, with a sensitivity of 69.1% vs 67%, specificity 60.9% vs 55%, and area under the curves (AUCs) of 0.672 and 0.643 respectively (p <0.001). Multivariate logistic regression analysis demonstrated that parity (OR 2.70), cervical length (OR 0.925), Bishop score (OR 1.272) and presence of funnelling (OR 3.292) were highly significant as independent predictors of success labour induction. Women also expressed significantly less discomfort with transvaginal ultrasound compared with digital vaginal examination. Sonographic assessment of cervical measurement predicts the success of induction of labour with similar diagnostic accuracy with conventional Bishop score.