A 25-year-old primigravida at 41 weeks undergoes induction with oxytocin. After 8 hours, she reaches 6 cm dilation. After 4 more hours at 6 cm with adequate contractions (Montevideo units 250) and ruptured membranes, there is no cervical change. According to ACOG/SMFM criteria, this is defined as?

• A Protracted active phase
• B Prolonged latent phase
• C Arrest of descent
• D Active phase arrest ✓

Explanation

Active phase arrest is defined as 6 cm or greater cervical dilation with ruptured membranes and no cervical change for 4 or more hours with adequate uterine activity (Montevideo units greater than 200), or 6 hours with inadequate contractions. This replaces the old Friedman criterion of 2 hours without change. Protracted active phase refers to slower than normal dilation rate (less than 1 cm/hr in nullipara). Arrest of descent applies to the second stage.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.