Induction Of Labour Flashcards
What is induction of labour?
When labour induced artificially
What percentage of UK labours are induced?
Approximately 20%
What indications are there for induction?
As a general rule: IOL performed when it thought that the baby will be safer delivered than remaining in utero or may be for reasons concerning the mother’s health.
Prolonged pregnancy - offer IOL between 40+0 to 40+14 to reduce risk of fetal compromise and stillbirth associated with prolonged gestation
Premature rupture of membranes (>37 weeks) offer IOL or expectant management for max 24 hours
For preterm premature rupture <34w delay IOL unless obstetric factors indicate otherwise e.g fetal distress
For PPROM >34w the timing of IOL depends on risks vs benefits of delaying pregnancy further e.g increased infection risk
Maternal health problems - HTN, pre-eclampsia, DM, obstetric cholestasis
Fetal growth restriction (second most common indication for IOL)
Intrauterine fetal death - if mother physically well with intact membranes
What contraindications are there?
Malpresentations Fetal distress Placenta praevia, vasa praevia Cord presentation Pelvic tumour e.g cervical fibroid Two or more previous low transverse CS
What methods are there?
Membrane sweep
Intravaginal prostaglandins
Breaking of waters - amniotomy
Oxytocin
When an induction is being planned, what is assessed?
The state of the cervix
What is the modified Bishop’s score?
A score to help assess whether induction of labour will be required
Score <5 labour unlikely to start without induction
Score >7 induction with artificial rupture of membranes should be possible, thereby avoiding prostaglandins
Score >9 labour most likely commence spontaneously
What factors does the Bishop score take into consideration?
Cervical dilation
Length of cervix
Station of head - cm above ischeal spines
Cervical consistency - firm, medium, soft
Position of cervix - posterior = 0, middle =1, anterior = 2
Induction is carried out using prostaglandin PEG2 in the form of…
A 10mg/24 hour pessary (1 cycle) or
vaginal gel 1-3mg 2 doses (1 cycle), second dose if labour has not started 6 hours after first
There is a recommended max of one cycle in 24 hours (IOL can sometimes take multiple days)
Prostaglandins prepare the cervix by ripening it and also have a role in the contraction of the smooth muscle of the uterus
What should be done pre and post prostaglandin PEG2 use?
CTG monitoring prior to use and for 30 mins post insertion
Prostaglandins may stimulate uterine contractions or precipitate labour
After spontaneous/artificial rupture of membranes, what should be done?
Start intrapartum fetal HR monitoring using CTG
If liquid clear, allow woman to mobilise for 2-4 hours to allow spontaneous contractions to start
If not contracting after this time - start oxytocin IV in 0.9% saline using pump, increasing amount until 4 contractions in 10 minutes
What should you be wary of when using oxytocin for induction?
Fetal distress
Uterine hyperstimulation: >5 contractions in 10 minutes
Why is induction of labour controversial in a woman with a previous C section?
Increased risk of scar rupture with prostaglandins and oxytocin infusions
Misoprostol - prostaglandin E1 analogue PO or PV is as effective at cervical ripening and induction of labour and PEG2 and oxytocin
Why is stillbirth associated with prolonged gestation?
Thought to be secondary to placental ageing
If a woman has had a previous Caesarean section, can IOL be offered?
Yes after she has been seen and assessed by a consultant
Mother should be made aware of an increased risk of emergency CS and uterine rupture
