BACKGROUND AND PURPOSE:

• Cesarean delivery and prolonged labor are both associated with maternal and neonatal morbidities
• A validated predictive calculator to predict risk of cesarean for women undergoing induction of labor is publicly available
• Hamm et al. (Am J Perinatol, 2019) investigated whether an increased risk for cesarean section using this predictive algorithm was also associated with increased labor length and morbidity

METHODS:

• Retrospective study
• Validated calculator: http://www.uphs.upenn.edu/obgyn/labor-induction-calculator/
• Participant data
  • Full-term (≥37 weeks) | Singleton | Intact membranes | Unfavorable cervix (Bishop score ≤6/ dilation ≤2 cm)
  • Exclusion:  Women with a prior cesarean
• Women were grouped based on the predicted risk of cesarean at the start of labor induction (<20% | 20-39.9% | 40-59.9% | ≥60%)
• Primary outcomes
  • Length of labor: Defined as time from start of induction to delivery
  • Composite maternal morbidity: ≥1 of the following
    • Third- or fourth-degree lacerations | Endometritis | Blood transfusion | Wound infection | VTE | Hysterectomy | ICU admission | Death
  • Composite neonatal morbidity: ≥1
    • Blood transfusion | Encephalopathy | IVH | Severe RDS | NEC | Sepsis

RESULTS:

• 8,466 women included

Labor Length

• Each category increase in cesarean probability was associated with an increase in labor length (p < 0.001)
  • Cesarean risk category <20: 9.6 hours
  • 20-39.9: 10.8 hours
  • 40-59.9: 11.7 hours
  • ≥60% 11.9 hours

Maternal Morbidity

• Each category increase in cesarean probability was associated with an increase in maternal morbidity (p < 0.001)
  • Cesarean risk category <20: 2.6%
  • 20-39.9: 4.7%
  • 40-59.9: 5.1%
  • ≥60% 6.1%

Neonatal Morbidity

• Each category increase in cesarean probability was associated with an increase in neonatal morbidity (p < 0.002)
  • Cesarean risk category <20: 0.9%
  • 20-39.9: 1.5%
  • 40-59.9: 2.0%
  • ≥60% 2.2%

CONCLUSION:

• The validated calculator designed to predict risk of cesarean section was also able to predict  
  • Longer labor length
  • Increased maternal and neonatal morbidity

Learn More – Primary Sources:

Using the Probability of Cesarean from a Validated Cesarean Prediction Calculator to Predict Labor Length and Morbidity

Related ObG Topics:

A New Predictive Model for Successful Induction of Labor

Does Shortened Midtrimester Cervical Length Predict Preterm Birth?

What is the Length of Latent Phase that Defines a ‘Failed Induction of Labor’?

Does Increased Hydration or Dextrose Reduce Prolonged Labor?