Induction

Question 1

Define induction of labour

Answer 1

Initiation of contractions in pregnant woman who isn’t in labour to help her achieve vaginal birth within 24 - 48 hours

Question 2

Define hyperstimulation in induction of labour

Answer 2

> 5 contractions per 10 minutes averaged over 30 minutes

Question 3

Name 3 foetal indications for IOL

Answer 3

• Growth restriction (suggested 38 - 39.6 weeks)
• concurrent conditions: oligohydramnios, maternal comorbidity eg pre-eclampsia (34 - 37.6)
• DCDA twins with isolated foetal growth restriction (36 -37.6)
• DCDA twins with concurrent condition abnormal Doppler, maternal comorbidity (32 - 34.6)
• DCDA twins (38 - 38.6)

Question 4

Name 5 maternal indications for IOL

Answer 4

• Chronic ht (suggested iol 38 weeks)
• gestational ht (38 weeks)
• pre-eclampsia
  → mild (at diagnosis after 37 weeks)
  → severe (at diagnosis after 34 weeks)
• pregestational diabetes (37 - 39.6)
• gestational diabetes (38 - 39,6)

Question 5

Name an obstetric indications for IOL

Answer 5

Pprom (preterm premature ROM)

Question 6

Name 5 contraindications IOL

Answer 6

Any contraindication to vaginal delivery!

• placenta /vasa praevia
• cord compression, cord prolapse /presentation
• abnormal Fetal lie: transverse/oblique/breech
• prior classical cs, prior uterine surgery, prior uterine rupture
• active genital herpes
• pelvic abnormalities
• invasive ca cervix.

Without indication, avoid IOL < 39 weeks

Question 7

How predict success of IOL?

Answer 7

Bishop score. Need > 7

5 factors: dilatation, effacement, station, consistency, cervical position

Question 8

Name 3 methods of induction for poor bishop score

Answer 8

Mechanical
- balloon devices (first line)
(apply pressure to internal Os to stretch lower segment and release local prostaglandins. Simple, reversible, less side effects, cheap)
- stretch and sweep

Pharmacological
- prostaglandins
→ PGE2: Prandin gel, prepidil, dinoprostone
(dissolve collagen structural network of cervix. Can start oxytocin 6h later if required. Better pt acceptance, less need oxytocin, less operative risk than oxytocin)
→ synthetic pg e 1: misoprostol oral 200ug in 200 ml H2O, 20 ml every 2hx12 doses po
(stable at room temp, cheap, rapid, multiple routes administration. oxytocin can be started 6h later if required, but side effects )

Question 9

How induce using balloon catheter? Name a contraindication.

Answer 9

18 fr foley into intracervical canal past internal os. Inflate bulb with 30 - 60 ml H2O.
Fall out spontaneously after 24h.

C/i = low lying placenta eg APH, Rom, lower gut infection
Complications = fever, bleeding, displacement of presenting part, pre-labour rupture of membrane

Question 10

Name 2 side effects and 2 contraindications misoprostol

Answer 10

Side effects
- uterine hyperstimulation
- meconium stained liquor

Contraindications
- grand multiparity
- previous c/s or uterine surgery!

Question 11

Name 2 methods of induction in those with favourable bishop score, with their risks and benefits

Answer 11

Amniotomy
- contraindications: placenta praevia, vasa praevia, gut infection
- Risk cord prolapse
- use oxytocin early

Oxytocin
- ideal dose not known so high and low dose protocols
- low dose: less hyperstimulation, smaller overall dose
- high dose: reduced length to labour, increased hyperstimulation
- continuous ctg needed

Question 12

Name 7 complications IOL

Answer 12

• Uterine rupture
• Failed induction
  → Risk factors: nulliparity, obesity, unfavourable cervix (low bishop score)
  → wait 24h before diagnose failed. = not in active labour/ not favourable bishop score
• prolonged first stage labour
• operative vaginal delivery
• caesarean delivery
• hyperstimulation
• foetal distress

Question 13

Dose misoprostol for IOL?

Answer 13

25 micrograms every 2 hours
X12 doses for maximum 72 hours

Check ctg before each dose

Prep: add 1 tablet (cytotec 200 micrograms) to 200 ml water. Drink 25 ml every 2 h, will give 8 doses

Question 14

Dose prandin gel for IOL?

Answer 14

1 mg ( 2 mg first dose)
Every 6 hours
X 3 doses

(PGE2)