Active labor arrest

  • First stage: between onset of labor and full cervical dilation
    • Latent: onset of labor to 6 cm cervical dilation

      • Characterized by slower cervical change, can last up to 20 hours
    • Active: 6 cm to full cervical dilation

      • Cervix should dilate 1.2–1.5 cm per hour
      • No change for 4 hours with adequate contractions = arrest of labor —> C-section
      • With oxytocin for inadequate contractions —> no change for 6 hours = arrest of labor—> C-section
    • Arrest of labor should not be diagnosed if membranes are not ruptured

Quantitative measure of adequate contractions?

  • 200 Montevideo units as measured by an intrauterine pressure catheter.