In a term singleton pregnancy with cephalic presentation and no obstetric complications, what are the stages of labour and how should each stage be managed?

Stages of Labour and Management

Overview of Labour Stages

Labour is divided into three stages: the first stage (from onset of labour to complete cervical dilation), the second stage (from complete dilation to delivery of the fetus), and the third stage (from delivery of the fetus to expulsion of the placenta). 1

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First Stage of Labour

Definition and Phases

The first stage consists of two phases—latent and active—with the transition determined by an accelerating cervical dilation rate rather than a specific centimeter measurement. 1

Latent Phase:

• Extends from onset of painful contractions until cervical dilation rate accelerates 1
• Median duration is 16.0 hours (IQR 10.0-26.6) in nulliparous women and 9.4 hours (IQR 5.9-15.3) in multiparous women 2
• No specific dilation threshold defines the end of latent phase 1

Active Phase:

• Begins when cervical dilation rate accelerates from the flat slope of latent phase, detected through serial vaginal examinations performed at least every 2 hours 1
• The steepest increase in dilation occurs between 5 cm and 6 cm 1
• Contraction strength, pain intensity, or specific dilation measurements do not reliably demarcate active labour onset—only the observed increase in dilation speed 1

Normal Progression Rates

Active phase dilation rates:

• Nulliparous patients: ≥1.2 cm/hour 1
• Multiparous patients: ≥1.5 cm/hour 1
• Rates below these thresholds indicate a protracted active phase requiring intervention 1

Monitoring Protocol

• Perform serial cervical examinations at minimum 2-hour intervals to track dilation progress 1
• Plot cervical dilation on a partogram to visualize rate of progress and promptly identify deviations 1
• Continuous fetal heart rate monitoring is recommended 3
• Assess uterine contractions, though palpation or Montevideo Units provide limited information for determining active-phase onset 1

Management of Normal First Stage

• Allow mobility and activity during labour 4
• Provide adequate pain management, with epidural analgesia preferred as it stabilizes cardiac output 1
• Use intermittent auscultation when appropriate 4
• Employ nonpharmacologic pain relief methods 4

Abnormal Labour Patterns and Management

Protracted Active Phase (dilation slower than normal thresholds):

Critical pre-intervention assessment:

• Evaluate for cephalopelvic disproportion (CPD), which occurs in 25-30% of active phase abnormalities 3
• Assess fetal position for malposition (occiput posterior/transverse) 3
• Evaluate for excessive molding, deflexion, or asynclitism without descent 3
• Consider fetal macrosomia, maternal diabetes, obesity, and pelvic adequacy 3
• Perform suprapubic palpation to differentiate true descent from molding 3

Management algorithm when CPD is excluded:

• Perform amniotomy combined with oxytocin augmentation 3
• Start oxytocin at 1-2 mU/min, increase by 1-2 mU/min every 15 minutes 3
• Target 7 contractions per 15 minutes, maximum dose 36 mU/min 3
• Monitor carefully for uterine hyperstimulation 3
• Perform serial cervical examinations every 2 hours after amniotomy 3

Decision points:

• If no progress after 4 hours of adequate contractions at 4-5 cm dilation, reassess for CPD 3
• At 6 cm or beyond, consider cesarean delivery after only 2 hours of arrest, as 4 hours may be excessive 3
• If CPD is confirmed or suspected at any point, proceed to cesarean delivery 3
• Immediately discontinue oxytocin if uterine hyperstimulation or fetal distress develops 3

Arrest of Dilation:

• Defined as absence of cervical change despite adequate observation and sufficient contractions 1
• Manage similarly to protracted active phase with amniotomy and oxytocin if CPD excluded 3

Risk factors for first stage abnormalities:

• Cephalopelvic disproportion 1
• Excessive neuraxial block 1
• Poor uterine contractility 1
• Fetal malpositions or malpresentations 1
• Maternal obesity 1
• Advanced maternal age 1

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Second Stage of Labour

Definition and Duration

• Begins at complete cervical dilation (10 cm) and ends with delivery of the fetus 1
• Allow 2-3 hours for the second stage 1

Management

• Consider assisted vaginal delivery (forceps or vacuum) if spontaneous delivery cannot be achieved rapidly 1
• Avoid prolonged bearing down efforts to prevent complications 1
• Monitor for failure of descent, which indicates inadequate fetal descent 1

Special Considerations

• Prolonged deceleration phase in first stage is strongly associated with second-stage abnormalities and increased risk of shoulder dystocia 1
• This reinforces the need for careful assessment and timely decision-making regarding mode of delivery 1

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Third Stage of Labour

Definition and Duration

The third stage extends from delivery of the fetus to expulsion of the placenta. 5, 6

• Normal duration is up to 1 hour if not actively managed 1
• The term "active management of the third stage" should no longer be used as a combined intervention; instead, implement individual evidence-based "third stage care" practices 6

Evidence-Based Third Stage Care

Uterotonic prophylaxis (most critical intervention):

• After vaginal delivery: Use oxytocin plus ergometrine, oxytocin plus misoprostol, or carbetocin 6
• After cesarean delivery: Use carbetocin or oxytocin as a bolus 6
• Oxytocin is the uterotonic drug of choice, though availability and storage may be challenging in resource-limited settings 5
• Avoid ergometrine as a standalone agent (contraindicated) 1

Cord clamping:

• Perform delayed cord clamping (after approximately 3 minutes) to allow placental transfusion, which increases infant red cell mass 5, 6
• Delayed clamping is not associated with increased maternal blood loss (RR 0.89,95% CI 0.58-1.36 for postpartum hemorrhage >500 ml) 5
• Administration of uterotonic drugs immediately after delivery hastens blood transfer to the infant 5
• After placental transfusion is completed (about 3 minutes), clamp and cut the cord 5

Controlled cord traction:

• Use controlled cord traction when feasible after signs of placental separation 6
• This is part of reducing maternal blood loss and postpartum hemorrhage risk 5

Early skin-to-skin contact:

• Implement early skin-to-skin contact between mother and newborn 6

Physiologic Basis

• During normal third stage, uterine contractions lead to separation and expulsion of the placenta 6
• The goal is to minimize maternal blood loss while optimizing neonatal outcomes 5, 6

Comparison of Management Approaches

Evidence-based third stage care (recommended):

• Combines uterotonic drugs, delayed cord clamping (≈3 minutes), controlled cord traction, and early skin-to-skin contact 5, 6
• Reduces postpartum hemorrhage (RR 0.38,95% CI 0.32-0.46) and mean blood loss by 79 ml 5

Expectant management (not recommended):

• "Hands off" policy awaiting spontaneous placental delivery within 1 hour 5
• Associated with increased maternal blood loss and postpartum hemorrhage risk 5

Common Pitfalls to Avoid

• Do not clamp the cord immediately after delivery; wait approximately 3 minutes for placental transfusion 5, 6
• Do not use the outdated term "active management of the third stage" as a bundle, as not all historical components are evidence-based 6
• Do not omit uterotonic prophylaxis, as this is the most effective intervention for preventing postpartum hemorrhage 6