A 24-year-old primigravida at 40 weeks has been in the active phase of labour for 6 hours. Cervical dilation progressed from 4 cm to 5 cm over the last 3 hours despite adequate contractions (250 Montevideo units). Fetal heart rate is reactive. Which term BEST describes this labour abnormality?

• A Protracted active phase ✓
• B Prolonged latent phase
• C Active phase arrest
• D Precipitate labour

Explanation

Protracted active phase is defined as a rate of cervical dilation slower than the expected minimum (less than 1 cm/hour in nulliparas under the older Friedman criteria; under ACOG/Zhang redefined guidelines, dilation from 6 cm to 10 cm should take no more than expected norms, but slow progression before 6 cm with documented protraction is still recognized). Active phase arrest requires no change for ≥4 hours at ≥6 cm with adequate MVUs. Here she is at 5 cm, so it is protraction, not arrest.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.