What is the recommended management approach for the labour mechanism?

Management of Labour Mechanism

The recommended management approach for labour mechanism should avoid internal fetal monitoring, prolonged rupture of membranes (>6 hours), and episiotomy to reduce the risk of vertical transmission in patients with hepatitis C infection. 1

Normal Labour Mechanism

Labour progresses through several distinct phases:

1. First Stage:

   • Latent phase: Early cervical changes
   • Active phase: More rapid cervical dilation (typically begins at 5-6 cm)
   • Transition: Final cervical dilation to 10 cm

2. Second Stage: From complete cervical dilation to delivery of the fetus

3. Third Stage: From delivery of the fetus to delivery of the placenta

Evidence-Based Management Approaches

First Stage Management

• Diagnosis of Active Labour: Active phase typically begins at 5-6 cm dilation 1
• Uterine Contractility Assessment:
  • Objective measurement of uterine contractility via intrauterine pressure transducers has not proven useful in clinical decision-making 1
  • Simple palpation is usually sufficient to evaluate contractions unless prevented by obesity 1
• Oxytocin Use:
  • Indicated for initiation or improvement of uterine contractions to achieve vaginal delivery for fetal or maternal reasons 2
  • May be used in cases of uterine inertia to stimulate or reinforce labour 2

Labour Analgesia Considerations

For patients requiring intrathecal analgesia after inadvertent dural puncture:

• Initial bolus of 2.5 mg bupivacaine with up to 15 μg fentanyl is recommended 1
• For maintenance, use bupivacaine 0.1-0.125% with 2-2.5 μg/ml fentanyl 1
• Only anesthesiologists should administer medications through intrathecal catheters 1

Avoiding Complications in Labour

• Prevention of Vertical Transmission (HCV):
  • Avoid internal fetal monitoring 1
  • Minimize duration of membrane rupture (risk increases after 6 hours) 1
  • Avoid episiotomy 1

Third Stage Management

• Active Management of Third Stage:
  • Administration of oxytocin immediately after delivery of the fetus 3
  • Typical dose: 10 IU IV 3
  • Oxytocin is indicated to produce uterine contractions during the third stage and control postpartum bleeding 2
  • Avoid ergometrine in patients with hypertension, pre-eclampsia, cardiovascular or respiratory disease 3

Special Considerations

Patients with Hepatitis C

• Breastfeeding is safe and recommended unless nipples are cracked or bleeding 1
• If nipples are cracked or bleeding, breast milk should be expressed and discarded 1
• HCV status should not alter standard breastfeeding practices 1

Patients with Respiratory or Cardiovascular Disease

• Avoid ergometrine for third stage management 3
• Prefer oxytocin as it has not been associated with worsening lung function 3

Common Pitfalls to Avoid

1. Overdiagnosis of labour abnormalities: Ensure proper diagnosis of active labour before intervention
2. Unnecessary interventions: Routine amniotomy and early oxytocin use are not recommended without specific indications 4
3. Inappropriate management of third stage: The term "active management of third stage" as a combined intervention is being replaced by evidence-based "third stage care" focusing on specific beneficial interventions 5
4. Ignoring risk factors for vertical transmission: In HCV-positive patients, prolonged rupture of membranes significantly increases transmission risk (28 vs 16 hours in one study) 1

By following these evidence-based approaches to labour management, providers can optimize outcomes while minimizing unnecessary interventions and complications.