Labour Induction

Question 1

What is labour induction?

Answer 1

It is the stimulation of uterine contractions during pregnancy, before labour begins on its own, to achieve a vaginal birth

Question 2

When is labour induction generally indicated?

Answer 2

When it is thought that delivering the baby will be safer for the baby and the mother, than for the baby to remain in utero

Question 3

What are the four specific indications of labour induction?

Answer 3

Prolonged Gestation

Prelabour Rupture of Membranes

Maternal Health Problems

Fetal Health Problems

Question 4

At what gestation do we offer labour induction?

Answer 4

40 - 42 weeks

Question 5

What are the two risks of prolonged gestation, hence why we offer labour induction?

Answer 5

Fetal compromise

Stillbirth

Question 6

What is prelabour rupture of membranes?

Answer 6

It is the term used when a patient’s waters have broken prior to labour starting

Question 7

What four maternal health problems indicate labour induction?

Answer 7

Hypertension

Pre-eclampsia

Diabetes

Obstetric cholestasis

Question 8

What three fetal health problems indicate labour induction?

Answer 8

Fetal Growth Restriction

Oligohydramnios

Intrauterine Fetal Death

Question 9

What is fetal growth restriction? At what estimated weight percentile?

Answer 9

It is a condition in which a fetus is smaller than expected for its gestational age

< 10th percentile

Question 10

What is oligohydraminos?

Answer 10

It refers to amniotic fluid volume that is less than expected for the gestational age

Question 11

What is intrauterine fetal death?

Answer 11

It is when a fetus dies inside the womb before birth

Question 12

What are the two general categories of labour induction contraindications?

Answer 12

Absolute

Relative

Question 13

What are absolute contraindications of labour induction?

Answer 13

They define events that could cause a life-threatening situation, and therefore induction is essential

Question 14

What are the seven absolute contraindications of labour induction?

Answer 14

Cephalopelvic Disproportion

Vasa Praevia

Placenta Praevia

Prolapsed Umbilical Cord

Active Primary Genital Herpes

Foetal Distress

Oblique Lie

Question 15

What are relative contraindications of labour induction?

Answer 15

They define events that should be approached with caution, however, are frequently performed

Question 16

What are the three relative contraindications of labour induction?

Answer 16

Breech Presentation

Maternal Asthma

Previous C-Section

Question 17

What are the five mechanisms of labour induction?

Answer 17

Membrane Sweep

Vaginal Prostaglandins

Cervical Ripening Balloon (CRB)

Amniotomy

Prostaglandin Analogues

Question 18

What is a membrane sweep?

Answer 18

It is performed by inserting a gloved finger through the cervix and rotating it against the fetal membranes

Question 19

How does a membrane sweep induce labour?

Answer 19

This separates the chorionic membrane from the decidua

The separation releases natural prostaglandins in an attempt to initiate labour

Question 20

When are membrane sweep mechanisms recommended?

Answer 20

In patients who have a prolonged gestation date between 40 - 42 weeks

It is not considered a full method of inducing labour and is more of an assistance before full induction

By performing it, the likelihood of spontaneous delivery increases, reducing the need for a formal induction

Question 21

What is another name for vaginal prostaglandins E2?

Answer 21

Dinoprostone

Question 22

What is prostaglandins?

Answer 22

A hormone

Question 23

What is prostaglandins?

Answer 23

A hormone

Question 24

What are the two functions of prostaglandins?

Answer 24

It ripens the cervix

It contracts the smooth muscle within the uterus

Question 25

When is vaginal prostaglandins recommended?

Answer 25

It is the preferred management option when cervical ripening has not yet occurred, usually indicated by a Bishop’s score less than six

Question 26

What is the cervical ripening balloon procedure?

Answer 26

It involves the insertion of a silicone balloon into the cervix to prepare it for labour by ripening it

Question 27

When is cervical ripening balloon recommended?

Answer 27

This induction method is only selected if cervical ripening has not yet occurred, usually indicated by a Bishop’s score less than eight It is used as an alternative where vaginal prostaglandins is not preferred

Question 28

In which three circumstances is vaginal prostaglandins not preferred to induce labour?

Answer 28

A previous c-section When prostaglandins has failed In multiparous women > 3

Question 29

What is amniotomy?

Answer 29

It is where the membranes are ruptured artificially using an instrument called an amniohook This process releases prostaglandins

Question 30

What do we administer following amniotomy? Why?

Answer 30

An infusion of artificial I.V oxytocin This is used to achieve adequate contractions

Question 31

What contraction rate should we aim during labour induction?

Answer 31

4 contractions every 10 minutes

Question 32

When is amniotomy recommended to induce labour?

Answer 32

When cervical ripening has occurred

Question 33

Name two prostaglandin analogues

Answer 33

Mifepristone Misoprostol

Question 34

When are prostaglandin analogues recommended to induce labour?

Answer 34

When intrauterine fetal death has occurred

Question 35

In what two ways do we monitor labour induction?

Answer 35

Bishop score Cardiotocography

Question 36

What is the bishop score?

Answer 36

It is a pre-labour scoring system used to predict whether induction of labour will be required It can also be measured during induction of labour to monitor the progress

Question 37

What are the five criteria of the bishop score?

Answer 37

Dilatation (cm) Cervix length (cm) Position Consistency Fetal Station

Question 38

What does a bishops score > 8 indicate?

Answer 38

A successful induction of labour

Question 39

What does a bishops score < 8 indicate?

Answer 39

A score less than eight suggests cervical ripening may be required to prepare the cervix before induction

Question 40

What does a bishops score < 5 indicate?

Answer 40

Labour induction

Question 41

What does a bishops score < 5 indicate?

Answer 41

Labour induction

Question 42

How is cardiotocography (CTG) used to monitor labour induction?

Answer 42

It is used to assess the fetal heart rate and uterine contractions It is also used following an oxytocin infusion, to monitor the stimulated contractions

Question 43

What are the three complications of labour induction?

Answer 43

Induction Failure Uterine Hyperstimulation Cord Prolapse

Question 44

How do we manage induction failure?

Answer 44

We can offer these patients a further cycle of prostaglandins or a c-section

Question 45

What is uterine hyperstimulation?

Answer 45

It occurs when the contraction of the uterus is prolonged and frequent

Question 46

What labour induction mechanism is associated with uterine hyperstimulation?

Answer 46

Prostaglandins

Question 47

What are the three complications of uterine hyperstimulation?

Answer 47

Foetal Distress C-Section Uterine Rupture

Question 48

How do we manage uterine hyperstimulation?

Answer 48

We administer tocolytic agents, such as terbutaline

Question 49

What labour induction mechanism is associated with cord prolapse?

Answer 49

Amniotomy, particularly if the presentation of the fetal head is high