Induction of Labour Flashcards
When is induction of labour indicated?
prolonged pregnancy, e.g. 1-2 weeks after the estimated date of delivery
prelabour premature rupture of the membranes, where labour does not start
maternal medical problems: diabetic mother > 38 weeks, pre-eclampsia, obstetric cholestasis
intrauterine fetal death
What is the Bishop Score?
The Bishop score is used to help assess whether induction of labour will be required.
What are the components of the Bishop Score?
Cervical position, cervical dilation, cervical consistency, cervical effacement and station
How is a Bishop Score interpreted?
< 5 indicates that labour is unlikely to start without induction
>7 indicates that the cervix is ripe, or ‘favourable’ - there is a high chance of spontaneous labour, or response to interventions made to induce labour
What are methods of inducing labour?
- Membrane sweep
- Vaginal prostaglandin E2 - dinoprostone
- Oral prostaglandin E1 - misoprostol
- Oxytocin infusion
- Amniotomy
- Cervical ripening balloon
What are the NICE guidelines for Bishop Score usage?
If Bishop Score </=6
vaginal prostaglandins or oral misoprostol
mechanical methods such as a balloon catheter can be considered if the woman is at higher risk of hyperstimulation or has had a previous caesarean
If Bishop Score >6
Amniotomy +/- IV oxytocin infusion
What is the main complication of labour induction?
Uterine hyperstimulation - refers to prolonged and frequent uterine contractions - sometimes called tachysystole
What are consequences of uterine hyperstimulation?
intermittent interruption of blood flow to the intervillous space over time may result in fetal hypoxemia and acidemia
uterine rupture (rare)
How is uterine hyperstimulation managed?
removing the vaginal prostaglandins if possible and stopping the oxytocin infusion if one has been started
consider tocolysis
