What is the expected time to delivery for a woman who is 5 cm dilated in active labor?

Time to Delivery from 5 cm Dilation

For a woman at 5 cm dilation in active labor, expect approximately 5-8 hours to delivery for nulliparous women and 3-6 hours for multiparous women, though significant individual variation exists. 1, 2

Expected Duration by Parity

Nulliparous Women

• Mean active phase duration (from 4 cm to complete dilation): 7.7 hours 2
• Statistical upper limit (2 standard deviations): up to 17.5 hours remains within normal range 2
• Since active phase begins around 5-6 cm per WHO/FIGO guidelines, a woman at 5 cm is at or near the beginning of active labor 1, 3
• Add approximately 54 minutes (mean) for second stage, with upper normal limit of 146 minutes 2

Multiparous Women

• Mean active phase duration (from 4 cm to complete dilation): 5.6 hours 2
• Statistical upper limit: up to 13.8 hours remains normal 2
• Mean second stage: 18 minutes, with upper limit of 64 minutes 2

Critical Factors Affecting Duration

Variables that prolong labor include: 2

• Electronic fetal monitoring (versus intermittent auscultation)
• Maternal age over 30 years
• Narcotic analgesia use
• Epidural analgesia (prolongs second stage specifically) 4

Importantly, longer labors within these ranges are NOT associated with increased morbidity 2

Clinical Context and Pitfalls

Understanding Active Phase Onset

• The 5 cm threshold represents the lower limit where active phase may begin, with 6 cm being more definitive 5, 1, 3
• Many nulliparous women are already in active phase before reaching 6 cm, while others remain in latent phase even after 6 cm 1, 3
• The pattern of cervical dilation rate is more important than a single measurement 1

When to Diagnose Labor Abnormalities

• Do not diagnose protraction disorder until observing dilation rate <0.6 cm/hour for at least 4 hours 5
• Do not diagnose arrest disorder until no cervical change for 2-4 hours in established active phase 5
• Recent evidence suggests 2 hours may be safer than 4 hours for determining arrest after 6 cm 5

Common Pitfalls to Avoid

• Do not assume all women at 5 cm will follow identical time courses - individual variation is substantial 1, 2
• Do not intervene with oxytocin based solely on time expectations - intervention requires documented protraction or arrest disorder 5
• Do not apply rigid time limits - the upper statistical limits (17.5 hours for nulliparas, 13.8 hours for multiparas from 4 cm) represent normal variation without increased morbidity 2

Practical Algorithm for Assessment

Serial cervical examinations every 2 hours are recommended to assess labor progression 5

If progress is slower than expected:

1. Verify active labor is established (not still in latent phase)
2. Exclude cephalopelvic disproportion before any intervention 5
3. Document specific abnormality (protraction <0.6 cm/hour or arrest with no change for 2-4 hours) 5
4. Only then consider oxytocin augmentation if CPD excluded 5