A primigravida is in active labour. Cervix is 6 cm dilated, 80% effaced, vertex at 0 station. After 2 hours of adequate uterine contractions (3 in 10 min, each >40 sec), there is no change in cervical dilation. This pattern is BEST described as:

• A Protracted active phase dilation
• B Latent phase prolongation
• C Arrest of active phase (active phase arrest) ✓
• D Secondary arrest of descent

Explanation

Active phase arrest is defined as no change in cervical dilation for ≥4 hours in the presence of adequate uterine contractions (≥200 Montevideo units), or ≥6 hours with inadequate contractions. However, 2 hours with adequate contractions and no progress in a primigravida at 6 cm warrants assessment and consideration of amniotomy and/or oxytocin augmentation. Protracted active phase is slower than expected progress, not arrest. The patient has adequate contractions with zero dilation change — this is active phase arrest (meeting criteria for intervention at 4 hours, though 2 hours prompts evaluation).

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.