Indications for Induction of Labour (IOL)
Induction of labour is warranted when continuing the pregnancy poses risks to the mother or foetus, or when the benefits of delivery outweigh those of continuing the pregnancy. Common indications include:
- Post-term pregnancy without spontaneous labour (usually offered at between 41-42 weeks gestation).
- Pre-labour rupture of membranes (PROM)
- Gestational hypertension
- Foetal growth restriction
- Maternal medical conditions such as diabetes or pre-eclampsia.
Bishop Score
- The Bishop score can be used to predict whether IOL will be successful. It assesses cervical readiness for labour induction based on cervical dilation, effacement, station, consistency, and position.
- A score of 6 or less indicates an unfavourable cervix, whereas a score higher than 6 suggests a favourable cervix for induction.
Strategies for Induction of Labour
- Membrane Sweep:
- Inserting a finger into the cervix to separate the amniotic membranes from the lower uterine segment. Stimulates prostaglandin release, which can initiate labour within 48 hours.
- Inserting a finger into the cervix to separate the amniotic membranes from the lower uterine segment. Stimulates prostaglandin release, which can initiate labour within 48 hours.
- Dinoprostone (Prostaglandin E2)
- Indicated in women with an unfavourable cervix (Bishop Score ≤6).
- Administered as vaginal gel, tablet, or slow-release pessary to soften the cervix.
- Amniotomy (Artificial Rupture of Membranes - ARM) followed by IV Oxytocin Infusion
- Recommended for women with a favourable cervix (Bishop Score >6).
- ARM involves deliberate breaking of the amniotic sac followed by IV oxytocin infusion to stimulate uterine contractions.
Complications
- Potential complications include
- Uterine hyperstimulation
- Foetal distress
- Increased risk of instrumental delivery or caesarean section.
References
- Inducing labour. NICE guideline [NG207]Published: 04 November 2021. Available here.