Induction + Augmentation of Labour

Question 1

Definitions of Induction and Augmentation of Labour?

Answer 1

• Induction = process of causing labour to commence (and continue)
• Augmentation = stimulation of labour that has already commenced (but isn’t going as fast/well as it should).

Question 2

Reasons to induce labour?

Answer 2

• Postmaturity = due date + 10-14days
  
  • US confirmation - LMP insufficient
  • placenta doesn’t live forever
• HTN disease/preeclampsia
• DM - 10% women
  
  • depends on control - can be managed
  • medications required for control
• ROM - rupture of membranes +/- chorioamnionitis
  
  • may not deliver if premature (e.g. <30weeks) without signs of infection
• FGR - signs of abdo and US parameters
• Foetal compromise - CTG, baby movement
• Blood group isoimmunization - rare due to anti-D (rhesus factor made rare), Kell more common now
• Placental abruption - seperates from attachment to uterus (pain + bleeding)
• Others:
  
  • Twin pregnancy - often need to be delivered but often deliver themselves, rarely get to 40wks. DM/HTN
  • Foetal death in utero (anencephaly, Potter’s, abruption, cord)
  • Significant foetal abnormality (termination of pregnancy)
  • poor past Obs Hx - difficulty in the past.

Question 3

Reasons not to induce labour?

Answer 3

• prematurity
• FGR
• Foetal compromise
• breech presentation/transverse lie
• placental praevia (lying low in uterus and potentially covering cervix).
• cephlopelvic disproportion (not in women who have previously had a cs)
• vaginal birth contraindication:
  
  • active HSV
  • placental pathology/malpresentation

may be better for cs = foetal/maternal compromise in labour process (induction can take >24hrs)

Question 4

What are some methods for induction?

Answer 4

1. Prostin E2

• used when cervix is closed
• pre-packaged syringe inserted into the vagina + topically applied
• PG - softens + partially dilates cervix
• CTG monitoring - may require multiple doses
• SE:
  
  • uterine hyperstimulation = response dramatic - can result in uterine rupture
• CI - uterine scar, ROM

1. Amniotomy/ARM

• hook/small toothed forceps used to rupture forewaters.
• cervix needs to be slightly dilated
• CI - may result in cord prolapse if presenting part not well applied. Uncomfortable for women.
• increased Haemorrhage risk. Pain. Prolapse of cord.

1. Syntocinon

• posterior pituitary polypeptide that stimulates uterine muscle contractions
• IV infusion - carefully titrated every 30mins
• CTG monitoring
• SE - hyperstimulation (foetal distress), N/V, hyponatremia

Others: - cervical balloon catheter

Question 5

What are some ways to Augment Labour?

Answer 5

• Forceps
  
  • Neville Barnes = anterior position of foetal head. Occiput anterior.
  • Kielland’s = used to rotate body - rarely used for complications (turn OP to OA) - ventouse and hand can also rotate
• Ventouse vacuum delivery
  
  • not possible to pull too hard
  • will pop off if the head is too big/pelvis too small
• must consider station:
  
  • baby’s head must have at least reached ischial spines
    
    • mid - head is engaged
    • low - lower than ischial spines
    • outlet - head is stretching perineum

Question 6

What are the reasons for augmentation of labour?

Answer 6

• delay in second stage of labour
  
  • exhaustion
  • epidural effective
  • malabsorption of presenting part
• foetal distress ni 2nd stage of labour

Question 7

What are some augmentation of labour techniques you should do?

Answer 7

• appropriate analgesia
  
  • spinal analgesia
  • GA not used
  • Pudendal block with perineal infiltration
• Lithotomy position (stirrups)
• Catheter passed
• cephalic position
• appropriate resus
• may need episiotomy

Question 8

What are complications of using augmentation?

Answer 8

• bruised baby
• facial nerve palsy (generally temporal)
• intracranial bleeding
• damanged c-spine
• temporary chignon (few hrs) + circular bruise
• soft tissue tears

Question 9

A patient has ROM in labour at term and meconium-stained liquor is present. What is the management and concerns?

Answer 9

• meconium - spontaneously but is a concern as it may be caused by fetal distress.
  
  • CTG monitoring + fetal scalp blood pH
  • cause investigation (listeria a common cause - give penicillin)
• complications:
  
  • meconium aspiration disease. Suction prior to stimulation of fetus.
• post delivery:
  
  • apgar >5 montior 2 hourly till 12 hrs old.
  • sick - neonatal resus.

Question 10

How would you assess someone for suitability of IOL?

Answer 10

• indication
• gestational age
• suitability/contraindications
• maternal aversion/risk tolerance
• bishop’s score
  
  • <5 use prostin gel/transcervical catheter
• fetal wellbeing (AFI, movement, growth, CTG)

Question 11

What are some complications of induction?

Answer 11

• cord prolapse
• uterine hyperstimulation
• fetal distress
• precipitate labour
• failed induction (CS necessary - in about 10%)