Diagnosis of Arrest of Cervical Dilatation

Diagnostic Criteria

Arrest of cervical dilatation is diagnosed when there is no cervical change for at least 4 hours despite adequate uterine contractions (≥200 Montevideo units) after the patient has reached at least 6 cm of cervical dilatation in the active phase of labor 1, 2
Cervical dilatation must be ≥6 cm to diagnose active phase arrest 1, 2
No cervical change for ≥4 hours with adequate contractions, or no cervical change for ≥6 hours with inadequate contractions despite oxytocin augmentation 1, 2

Perform vaginal examinations at least every 2 hours to accurately track the rate of cervical dilatation 3, 4
The active phase begins when the rate of dilatation transitions from the flat slope of latent phase to more rapid progression, regardless of the specific degree of dilatation achieved 3, 4

Document cervical dilatation, effacement, and fetal station at each examination 1, 2
Monitor fetal heart rate continuously to ensure normal fetal well-being during the assessment period 1, 2
Assess for adequate uterine contractions using internal pressure monitoring when possible 2

Do not diagnose arrest before 6 cm dilatation—this represents latent phase, not active phase arrest 1, 2
Do not rely on contraction assessment alone (palpation or Montevideo units) to determine if active phase has begun, as contractions increase inconsistently and provide limited diagnostic value 3, 4

Cephalopelvic disproportion (CPD) occurs in 25-30% of active phase arrest cases 1, 2
Fetal malposition or malpresentation may contribute to arrest 3, 4
Excessive neuraxial analgesia may contribute to arrest 3, 4
Maternal factors such as obesity, advanced maternal age, and diabetes may contribute to arrest 3, 4, 5
Fetal macrosomia may contribute to arrest 5
Intrauterine infection may contribute to arrest 3, 4