What is the management for a multigravida (multiparous woman) at 39 weeks gestation with a favorable Bishop score, 5 cm cervical dilation, and strong regular contractions after 4 hours of active labor?

Management: Amniotomy Combined with Oxytocin Augmentation

This patient has protracted active phase labor (1 cm dilation over 4 hours = 0.25 cm/hour, well below the threshold of 0.6 cm/hour), and the American College of Obstetricians and Gynecologists recommends amniotomy combined with oxytocin augmentation as the evidence-based approach when cephalopelvic disproportion (CPD) is not evident. 1

Why This is Protracted Active Phase Labor

• The patient is in active labor at 5 cm dilation with strong, regular contractions and a fully effaced cervix, but her cervical dilation rate of 0.25 cm/hour over 4 hours indicates protracted progress. 1
• The favorable Bishop score confirms she is appropriate for augmentation rather than cesarean delivery at this stage. 1

Critical Pre-Intervention Assessment Required

Before proceeding with augmentation, you must evaluate for CPD, which occurs in 25-30% of active phase abnormalities: 1

• Assess fetal position for malposition (occiput posterior/transverse). 1
• Evaluate for excessive molding, deflexion, or asynclitism of the fetal head without descent. 1
• Perform suprapubic palpation of the base of the fetal skull to differentiate true descent from molding. 1
• Consider fetal macrosomia and pelvic adequacy as contributing factors. 1

Why Each Answer Option is Right or Wrong

Option C (Amniotomy) combined with Option B (Oxytocin) is correct:

• Amniotomy alone rarely produces further dilation, and the American College of Obstetricians and Gynecologists recommends combining it with oxytocin augmentation for protracted active phase labor. 1

Option D (Reassess after 2 hours) is incorrect:

• She has already demonstrated inadequate progress over 4 hours; further observation without intervention will only prolong labor unnecessarily. 1

Option A (Cesarean section) is premature:

• Cesarean delivery is only indicated if CPD is confirmed or suspected, or if augmentation fails after 4 hours of adequate contractions. 1, 2

Oxytocin Administration Protocol

Start oxytocin at 1-2 mU/min and increase by 1-2 mU/min increments every 15 minutes, targeting 7 contractions per 15 minutes, with a maximum dose of 36 mU/min. 1, 3

• Monitor continuously for fetal heart rate patterns, contraction frequency, duration, and intensity. 1, 3
• Watch for signs of uterine hyperstimulation and discontinue oxytocin immediately if it occurs. 1, 3

Monitoring and Decision Points

• Perform serial cervical examinations every 2 hours after amniotomy to assess progress. 1
• If no progress occurs after 4 hours of adequate contractions, reassess for CPD. 1, 2
• If CPD is confirmed or suspected at any point, proceed to cesarean delivery. 1
• Recent evidence suggests that allowing 4 hours of arrest may be too long after 6 cm dilation, with 2 hours being safer. 1

Critical Pitfall to Avoid

Watch for increasingly marked molding, deflexion, or asynclitism without descent during augmentation—these are signs of emerging CPD that mandate cesarean delivery. 1 The success rate for vaginal delivery with oxytocin augmentation is 92% when CPD is not present, but this requires vigilant monitoring for signs of obstruction. 2