Induction of labour Flashcards
What is the definition of ‘induction of labour’?
the initiation oflabourby artificialmeansprior to its spontaneous onset at a viable gestational age, with the aim of achieving vaginal delivery in a pregnant woman with intact membranes
What are some obstetric indications for induction of labour?
Uteroplacental insufficiency
Prolonged pregnancy
Intrauterine growth retardation
Prelabour rupture of membranes
Antepartum haemorrhage
Poor obstetric history
Intrauterine death
Maternal request (exceptional circumstances)
What are some medical indications for induction of labour?
Severe HTN
Uncontrolled DM
Renal disease
Malignancies (facilitate definitive therapy)
When does NICE say induction go labour should be done?
Benefit > risk
The process of induction of labour should only be considered when vaginal delivery is felt to be the appropriate route of delivery
Why is IoL important in prolonged pregnancy?
Pregnancy extends past the due date there is increase in perinatal mortality as a result of decreased placental function
Why are pre-labour rupture of membranes a concern?
Risk of infection to baby - contact with outside world
What are some ABSOLUTE contra-indications for IoL?
Acute fetal compromise
Unstable lie
Placenta praevia
Pelvic obstruction
What are some relative contraindications for IoL?
Previous cs
Breech
Prematurity
High Parity
What things do people often believe are useful for IoL BUT ARE NOT supported by evidence?
herbal supplements acupuncture homeopathy castor oil hot baths enemas sexual intercourse
What is membrane sweeping? When is it done?
Type of vaginal examination - aka stretch and sweep
Artificial membrane separation
Done before induction to try and prevent the need for full induction (hope this will start labour by releasing prostaglandins)
How is a membrane sweep done?
Finger into cervical os which digitally separates the membranes of the cervix
May be done once, or additional sweeping may be offered
When is a membrane sweep done in a nulliparous woman?
40-41 week antenatal visit
When is a membrane sweep done in a multiparous woman?
41 week antenatal visit
Other than brining on labour, what else might a membrane sweep result in?
‘more favourable’ cervix
what percentage of women go in to spontaneous labour within 7 days of a membrane sweep?
30%
What scoring system is used to assess for favourability of IoL?
Modified Bishop’s score
What is the max score of Bishop’s score?
10
What Bishop’s score indicates a favourable cervix?
> 8
How is the position of the cervix scored in Bishop’s score?
Posterior: 0
Axial: 1
Anterior: 2
What is the preferred method of IoL?
Vaginal prostaglandins (PGE2)
What are the two main effects of PGE2?
Cervix: promotes ripening
Uterus: smooth muscle contraction
How is PGE2 given to patients? What delivery methods exist?
Given PV
Inserted into posterior fornix
Gel, tablet, suppository, pessary
Other than PGE2, what can be given to induce labour?
Oxytocin infusion (syntocinon)
Start low dose, titrate up
Why wouldn’t you give oxytocin infusion to a woman with a low bishop’s score?
Cervix wouldn’t be ready
oxytocin doesn’t have any impact on cervix
How does the length of cervix (degree of effacement) score on Modified Bishop’s score?
2cm = 0
1 cm = 1
<0.5cm = 2
Which symptoms post early rupture of membranes would make you worry about infection?
Vaginal discharge
Abdo pain
How does dilation of cervix score in Modified Bishop’s score?
0 cm = 0
1 cm = 1
> =2cm = 2
How does station of presenting part score on Modified Bishop’s score?
- 2 = 0
- 1 = 1
0 = 2
What would you need to assess prior to commencing IoL?
Favourability of cervix Obstetric examination (lie, cephalic presentation and engagement) - CALCULATE MODIFIED BISHOP'S SCORE
MEWS score
CTG
What is oxytocin?
Hormone released by posterior pituitary which causes smooth muscle of uterus to contract
When is oxytocin used?
Can be used to induce labour
MORE COMMONLY TO AUGMENT LABOUR
Other than to augment labour, when might oxytocin be given?
When membranes have ruptured (either naturally or artificially)
What do you need to monitor when giving a patient an IV oxytocin infusion?
CTG
What do you need to monitor when giving a patient an IV oxytocin infusion?
CTG (baby’s heart rate)
What can be done to cause membrane rupture in a lady who is undergoing IoL?
Artificial rupture of membranes (ARM)
aka: amniotomy
How is ARM/amniotomy done?
Ruptured tool - amnihook
What are the complications of IoL?
Foetal distress precipitate delivery instrumental/operative delivery uterine hypertonia with possible rupture amniotic fluid embolism systemic effects
Do you have to have consent for IoL?
Yes - need to explain reasons for induction and possible consequences of accepting/declining the procedure
