Indications, methods and complications

Question 1

What is IOL?

Answer 1

Labour that is induced artificially

Question 2

How is it different from Augmentation?

Answer 2

In augmentation, already established contractions are strengthened. IOL involves inducing labour, not building on pre-existing work

Question 3

Why is IOL performed?

Answer 3

Indicated in any situation where allowing the foetus/mother to a risk greater than that of induction (in reality, this quantification is rarely simple)

Question 4

What percentage of UK labours are artificially induced?

Answer 4

20%

Question 5

What are the reasons for the majority (75%) of IOLs?

Answer 5

HNT
Prolonged pregnancy (after 41 w, inc risk of stillbirth)
Pre-eclampsia
Rhesus disease

Question 6

What are less common (but still relevant) reasons for induction?

Answer 6

Diabetes (and other maternal medicine complications)
Previous stillbirth
Abruption
Foetal death in utero
Placental insufficiency
IUGR
Foetal congenital abnormalities
Pre-labour prolonged rupture of membranes

Question 7

What are contraindications?

Answer 7

Malpresentation (inc breech)
Foetal distress
Placenta praevia
Cord presentation
Vasa praevia
Pelvic tumour (e.g. cervical fibroid)

Question 8

What can be done to avoid IOL with medication?

Answer 8

Membrane sweep

There is no evidence for sex, castor oil, enemas, acupuncture, homeopathy, herbal supplements or hot baths

Question 9

What are the risks of IOL?

Answer 9

Prolonged labour duration
More likely to need regional anaesthesia (and an operative delivery)
Failure to establish labour (15%)
(NOT assoc with inc LSCS risk)
Postpartum haemorrhage
Intra and postpartum infection
Uterine hyperstimulation
Uterine rupture
Umbilical cord prolapse

Question 10

What are the risks of delay labour beyond 40+12?

Answer 10

Increased perinatal mortality

Increased risk of intervention (LSCS)

Question 11

What would a midwife typically do in a woman who has consented to IOL?

Answer 11

Confirm gestation
Palpate foetal lie, position and engagement
Perform CTG
Vaginal exam to assess cervical favourability

Question 12

What is Naegle’s rule?

Answer 12

LMP -3mo +7d

Question 13

When is the EDD typically calculated?

Answer 13

At dating scan (around 12w) from crown rump length

Question 14

How is the state of the cervix assessed?

Answer 14

Bishop’s score

Question 15

The risk of what increases if primips are induced with a Bishop’s <3?

Answer 15

Prolonged labour
Foetal distress
LSCS

Question 16

What is a favourable Bishop’s?

Answer 16

> 5

Question 17

What if Bishop’s >7?

Answer 17

Induction via ARM (avoids use of prostaglandins)

Question 18

What are the methods of IOL?

Answer 18

Prostaglandins (ripen cervix, enable amniotomy)
Amniotomy
Syntocinon infusion
Mechanical cervical dilators

Question 19

What forms of prostaglandin are available?

Answer 19

Pessary (Prostin) 10mg/24hr
Gel (Prostin gel) 1-3mg/6hrly
Slow-release preparation (Propess)

Question 20

When giving prostaglandins, what else should be performed?

Answer 20

CTG (pre PG use and 30mins after insertion

Question 21

How do prostaglandins induce labour?

Answer 21

Stimulate uterine contractions or precipitate labour

Question 22

If membranes cannot be ruptured 48hrs after PG use, what can be done?

Answer 22

Try IOL again

LSCS

Question 23

What is amniotomy?

Answer 23

Rupture of membranes, spontaneous or artificial (SRM/ARM)

Question 24

What is the woman at risk of from amniotomy?

Answer 24

Cord prolapse (MEDICAL EMERGENCY - compression/vasospasm that causes foetal asphyxia)

Question 25

How is cord prolapse managed?

Answer 25

Decompress cord by manual elevation of baby head and putting mother in prone knee-chest position or filling maternal bladder with saline Unless woman is fully dilated, LSCS needs to be performed

Question 26

What should be done to the foetus once amniotomy has occurred (SRM or ARM)?

Answer 26

Intrapartum CTG | Allow woman to mobilise for 2-4hrs to induce contractions (if liquor clear)

Question 27

What if woman is not experiencing contractions after amniotomy?

Answer 27

Oxytocin 1-4 milliunits/minute, increasing every 30 mins until woman experiencing 4 contractions every 10 mins (typically 4-10MU/min)

Question 28

When should oxytocin/IOL be stopped?

Answer 28

If CTG shows foetal distress or uterine hyperstimulation (>5 contractions/10 mins with foetal compromise)

Question 29

Should women with previous caesarean sections have IOL?

Answer 29

Consult with senior (inc risk of scar rupture with prostaglandins and oxytocin)

Question 30

What alternative medication can be used to induce labour (and what is the condition for its use)?

Answer 30

Misoprostol PO/PV has lower chance of hyperstimulation Only use for IOL after intrauterine death

Question 31

What analgesia options are available for women in labour?

Answer 31

``` Non-pharmacological -Hypnotherapy/relaxation techniques -Aromatherapy -TENS -Water Pharmacological -Simple analgesia -Opioids (include PCA for IUD or where RA is contraindicated); short-term neonatal effects if delivery within 2 hrs of pethidine -Entonox (gas and air) -Regional anaesthetic (RA); assoc with increased risk of instrumental delivery ```

Question 32

How is the dose of syntocinon (oxytocin) titrated?

Answer 32

Titrated against the rate of maternal contractions

Question 33

What are the pathological causes of abnormal CTGs?

Answer 33

Hyperstimulation Advancing labour (Foetal hypoxia main concern)

Question 34

How to manage abnormal CTG in IOL?

Answer 34

Assess progress using vaginal exam | Turn down syntocinon to reduce frequency of contractions

Question 35

What are the next steps if contraction rate is slowed but CTG still abnormal?

Answer 35

Without foetal blood sample, difficult to ascertain cause. | 50% of abnormal CTGs assoc with foetal compromise and so require urgent delivery

Question 36

What is a normal finding on foetal blood sampling?

Answer 36

>7.25 (would need repeating in 1 hr if CTG remained abnormal) If 7.20-7.25, repeat in 30 mins If <7.20 foetus at substantial risk of hypoxia and needs urgent delivery

Question 37

If FBS is 7.32, cervix fully dilated and foetus in OA, what is the best mechanism for delivery?

Answer 37

Instrumental delivery (no point waiting to repeat FBS as foetus easily deliverable)

Question 38

What should be performed once baby is delivered?

Answer 38

Cord gas analysis

Question 39

What instrument can be used to rupture membranes artificially?

Answer 39

Amnihook

Question 40

When is the best time to perform IOL?

Answer 40

38w