Prolonged Labour

Labor that extends beyond the expected duration for the stage of labor, most commonly used to describe a prolonged first or second stage, distinguished from obstructed labor by the absence of a true mechanical barrier to delivery, though prolonged labor can progress to obstruction if unaddressed.

Causes fall into the same broad categories as any delay: power (inadequate uterine contractions), passenger (fetal size, presentation, or position), and passage (pelvic shape or soft tissue resistance).

Slower than expected cervical dilation or descent of the presenting part on serial vaginal examination, maternal fatigue, and, if prolonged significantly, signs of maternal ketosis and dehydration.

• Partograph monitoring is central: the first stage is generally considered prolonged if cervical dilation progresses at less than 1 cm/hour in active labor (this threshold has been revisited in some more recent evidence suggesting normal active labor can progress more slowly, particularly in nulliparous women, and local protocols vary), formally flagged by crossing the alert line (prompting closer monitoring) and action line (prompting active intervention) on the partograph
• Second stage is generally considered prolonged beyond 2 hours in nulliparous women (3 hours with epidural analgesia) or 1 hour in multiparous women (2 hours with epidural), though again with some variation across guidelines
• Assessment for the underlying cause: contraction adequacy (frequency, strength, duration), fetal position and station, and pelvic assessment

• Amniotomy (artificial rupture of membranes), if membranes are intact, is a first step, often augmenting contraction efficiency
• Oxytocin augmentation, IV infusion, titrated per local protocol (typically started at a low rate and increased at set intervals to achieve adequate contraction frequency, generally 4 to 5 contractions per 10 minutes), used where contractions are assessed as inadequate
• Continuous fetal monitoring is generally recommended once oxytocin augmentation is started, given the increased risk of uterine hyperstimulation and fetal distress
• Reassessment after a defined period of augmentation (commonly 2 to 4 hours) determines whether progress is now adequate; failure to progress despite adequate contractions points toward a passenger or passage problem, and generally warrants cesarean section rather than continued augmentation
• Instrumental delivery (ventouse or forceps) is considered in the second stage where delay reflects inadequate maternal effort, malposition, or fetal distress, provided criteria for safe instrumental delivery are met (full dilation, appropriate station, no significant cephalopelvic disproportion)
• Adequate analgesia and hydration throughout, and correction of ketosis if present

Referral: obstetric-led care with escalation to senior obstetric review if progress remains inadequate despite augmentation.