Induction of labour (Complete) Flashcards
Define induction of labour
Artificial initiation of labour
What are the main indications for for induction of labour?
Post-term (>41 weeks)
Pre-term prelabour rupture of membranes
Intrauterine foetal death
Maternal conditions that can cause maternal/foetal comprimise
- Pre-eclampsia
- Diabetes
- Cholestasis
Abnormal CTG (foetal distress)
What are the contraindictions to induction of labour?
Previous classical C-section (vertical scar)
- Higher risk if uterine rupture
Multiple lower uterine segment C-sections
- Higher risk of uterine rupture
Transmissible infections
Placenta praevia
Malpresentations
Severe foetal comprimise
Cord prolapse
Vasa praevia
What can be offered pre-induction of labour?
Membrane sweep
Nulliparous women: Offer at 40-41 weeks
Multiparous women: Offer at 41 weeks
How does membrane sweep promote labour
Detatchment of membrane sac from cervix and lower uterine segment promotes release of prostaglandins and oxytocin
What risks are associated with membrane sweep?
Discomfort
Light bleeding
Infection
Premature rupture of membranes
Cramping
What are the steps involved in induction of labour?
Membrane sweep followed by:
1) Prostaglandin E2 (prefered) or Balloon catheter
2) Artifical rupture of membranes
3) Syntocinon for augmentation
4) C-section
What is typically given first-line in induction of labour?
Prostaglandin E2
How much prostaglandin E2 is administered?
Depends on method of administration
Pessary: 1 dose given over 24 hours
Oral/gel: 1 dose followed by 2nd dose 6 hours later
How does prostaglandin E2 promoted induction of labour?
Promotes uterine contraction and cervical shortening
What are the main risks associated with prostaglandin E2?
Uternine hyperstimulation (too many contractions in a short period of time)
Uterine rupture
Foetal distress due to hyperstimulation
PPH (due to uterine atony)
How does a balloon catheter cause induction of labour?
Balloon catheter inserted into cervix, inflated and left for 12-24 hours
Increased pressure promotes cervical shortening and release of prostaglandins
What risks are associated with balloon catheter induction?
Infection
Uterine perforation or injury
Discomfort
Catheter displacement
What alternative methods can be used if first-line measures for induction of labour have failed?
Artificial rupture of membranes (ARM)
How does ARM induce labour?
Rupturing the membranes releases prostaglandins circulating in the amniotic fluid.
Release of fluid also provides more space for foetal descent.
What risks are associated with ARM?
Infection
Umbilical cord prolapse
Increased risk of c-section if labour does not progress
Foetal distress or meconium aspiration (if the baby is in distress)
Chorioamnionitis
What is next step of induction of labour if ARM fails?
Syntocinon (oxytocin)
How is syntocinon administered?
Given 6 hours after prostaglandin if administered
IV oxytocin
- Initially 2-4 mU/min
- Increase by 2 mU/min every 20-30 minutes
- Maximum dose: 20 mU/min
Goal: 3-4 contractions per minute
What risks are associated with syntocinon?
Maternal hypotension (if given too quickly)
Water intoxication (if prolonged use at high doses)
Uterine hyperstimulation
Uterine rupture
Foetal hypoxia (poor blood flow due to excessive contractions)
PPH
What is last step in management if previous induction attempts have failed?
C-section
