BACKGROUND AND PURPOSE:

• Kamel et al. (AJOG, 2021) assessed the feasibility of developing and validating transabdominal and transperineal ultrasound for the prediction of cesarean delivery for failure to progress among women who are being induced

METHODS:

• Prospective observational cohort study
• Participants
  • Primigravidae | Singleton term pregnancies | Cephalic presentation
  • Exclusion: Operative delivery for fetal distress or indications other than failure to progress in labor
• Exposure
  • Baseline Bishop scoring
  • Transabdominal and transperineal ultrasound assessments of the fetus, maternal cervix, and pelvic floor
• Study design
  • Managing obstetricians were blind to the ultrasound findings
  • The participants were divided into a model development group and a cross-validation group
  • Following enrollment
    • Transabdominal scan: Fetal biometry | Fetal occiput position
    • Transperineal scan: Cervical length | Angle of progression (parameter for the assessment of the descent of the fetal head) AP diameter of the levator hiatus | Head-to-perineum distance | Head-to-symphysis distance
• Primary outcome
  • Cesarean delivery following induction for failure to progress

RESULTS:

• 243 women in model development group | 101 in cross-validation group
• The following were found to be independent predictive variables for cesarean delivery
  • Maternal age: odds ratio 1.12 (P = 0.003)
  • Cervical length: OR 1.08 (P = 0.04)
  • Angle of progression: OR 0.9 (P = 0.001)
  • Occiput posterior position: OR 5.7 (P = 0.006)
• AUC for ability of the model to predict cesarean delivery
  • Developed model: 0.7969 (95% CI, 0.71 to 0.87)
  • Validated model: 0.88 (95% CI, 0.79 to 0.97)

CONCLUSION:

• This study identified a combination of maternal age and ultrasound measurements obtained during induction that were good at predicting cesarean delivery due to failure to progress following induction of labor
• Digital examination can be inaccurate, especially with molding and/or caput 
• The authors state

On external validation, this prediction model has the potential to be a useful tool for clinicians and women to make management plans and informed healthcare choices by providing them with the individualized risk of cesarean delivery

Learn More – Primary Sources:

Predicting cesarean delivery for failure to progress as an outcome of labor induction in term singleton pregnancy

Role of intrapartum transperineal ultrasound: Angle of progression cut-off and correlation with delivery mode

Related ObG Topics:

Labor Induction and an Unripe Cervix: Does it Result in More C-sections?

A New Predictive Model for Successful Induction of Labor

Can the Cesarean Prediction Calculator Also Predict Labor Length and Morbidity?