A 28-year-old primigravida at 39 weeks is in active labour. Cervix is 7 cm dilated, fully effaced, vertex at -1 station. After 4 hours of adequate uterine contractions (3 per 10 min, each lasting 40 seconds), the cervix remains 7 cm. Fetal heart rate is normal with accelerations. According to ACOG guidelines, what is the diagnosis?

• A Protracted active phase
• B Normal labour with physiological delay
• C Prolonged latent phase
• D Active phase arrest ✓

Explanation

Active phase arrest is defined as no cervical change for 4 or more hours with adequate uterine contractions (Montevideo units >=200) at 6 cm or greater dilation with ruptured membranes. This patient meets all criteria: 7 cm, adequate contractions, no change for 4 hours. Active phase arrest requires intervention.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.