Labour - Special Circumstances

Question 1

What is successfulness of induction depend on?

Answer 1

State of ‘favourability’ of the cervix
often scored out of 10 as the ‘Bishop’s score’ - the lower the score the more unfavourable the cervix

Five things are assessed and given a score based on different criteria (minimum score is 0 and maximum is 13):

Fetal station (scored 0 – 3)
Cervical position (scored 0 – 2)
Cervical dilatation (scored 0 – 3)
Cervical effacement (scored 0 – 3)
Cervical consistency (scored 0 – 2)

A score of 8 or more predicts a successful induction of labour. A score below this suggests cervical ripening may be required to prepare the cervix.

Question 2

What are the components of the bishop’s score?

Answer 2

Cervical ‘consistency’

Degree of effacement or early dilation

How low the head is in the pelvis (station)

Cervical position (anterior or posterior)

Question 3

What are the methods of induction?

Answer 3

Membrane sweep involves inserting a finger into the cervix to stimulate the cervix and begin the process of labour - done over 40
Vaginal prostaglandin E2 (dinoprostone) involves inserting a gel, tablet (Prostin) or pessary (Propess) into the vagina. This stimulates the cervix and uterus to cause the onset of labour.

Cervical ripening balloon (CRB) This is used as an alternative where vaginal prostaglandins are not preferred, usually in women with a previous caesarean section, where vaginal prostaglandins have failed or multiparous women (para ≥ 3).

Artificial rupture of membranes with an oxytocin infusion can also be used to induce labour, although this would only be used where there are reasons not to use vaginal prostaglandins. It can be used to progress the induction of labour after vaginal prostaglandins have been used.

Question 4

How does cervical sweeping work?

Answer 4

Passing a finger through the cervix and stripping between the membranes and the lower segment of the uterus - at 40 weeks, this reduces the chance of induction and postdates pregnancy, but can be uncomfortable

Question 5

How does induction with prostaglandins work?

Answer 5

gel/slow-release preparation is inserted into the posterior vaginal fornix.

best method for nulliparous women and in multiparous women.

Starts labour OR ripeness of the cervix is improved to allow amniotomy

Question 6

How does ARM / oxytocin work?

Answer 6

Forewaters are ruptured with an amnihook

oxytocin induction is then started within 2 hours if labour has not ensued. oxytocin is often used alone if spontaneous rupture of membranes have already occurred, although PGs are effective

Question 7

What are the indications for induction of labour?

Answer 7

Foetal indications - high risk situations:
prolonged pregnancy
suspected IUGR or compromise
Antepartum haemorrhage
Poor obstetric history 
prelabour term rupture of membranes 

Materno-foetal indications - pre-eclampsia and maternal disease (e.g. diabetes)

Maternal indications - social reasons and in utero death

routine indications - studies show lowest perinatal and infant mortality rate is achieved by delivery at 38 weeks

Question 8

What are the absolute contraindications of induction?

Answer 8

Acute foetal compromise - abnormal CTG

Abnormal lie

Placenta praevia

Pelvic obstruction

> 1 C-section

Question 9

What are the relative contraindications of induction?

Answer 9

> 1 C section and prematurity

Question 10

What are the complications of induction?

Answer 10

Foetus - increased risk due to indications and drugs (CTG indicated)

Induction increases time spent in early labour - woman should be warned of this

labour may start to fail or be slow due to inefficient uterine activity - or overactivity of the uterus can occur. hyper stimulation causes foetal distress and even uterine rupture

Complications - PPH, intrapartum/postpartum infection, prematurity, instrumental delivery or C-section

Question 11

What are the contraindications of VBAC (vaginal birth after caesarean)?

Answer 11

all absolute indications for C-section

Vertical uterine scar

Previous uterine rupture

Multiple previous C-sections

Question 12

What % of women will deliver vaginally and by C-section if VBAC is attempted?

Answer 12

72-75% women will deliver vaginally

The others will require an emergency C-seciton in labour

Question 13

What are the factors associated with increased success of VBAC?

Answer 13

spontaneous labour

Interpregnancy interval <2 years

Low age and BMI

Caucasian race

Previous vaginal delivery

Previous elective C-section or due to foetal distress (not dystocia)

Question 14

In what % of VBACs does uterine rupture occur in?

Answer 14

1 in 200

Question 15

What is the risk of foetal mortality with VBAC?

Answer 15

same risk as found in 1st labour

Question 16

Why is delivery in hospital and with CTG monitoring advised?

Answer 16

Scar rupture

induction usually avoided as it is associated with a higher risk of rupture
augmentation also increases the risk of scar rupture

Question 17

What does scar rupture usually present with?

Answer 17

Foetal distress
Scar pain 
Cessation of contractions
Vaginal bleeding 
Maternal collapse

Question 18

In what % of women does prelabour term rupture of the membrane occur in?

Answer 18

10% women after 37 weeks

60% will start labour pithing 24 hours

Question 19

How does PROM present?

Answer 19

gush of clear fluid, which is followed by uncontrollable intermittent trickle

often confused with urinary incontinence

Point of care tests (actim PROM) may help where the diagnosis is not clear

Few only have hind water rupture - liquor leaks, but membranes remain intact in front of the foetal head

Question 20

What are the risks of PROm?

Answer 20

Cord prolapse - rare and usually a complication of transverse lie or breech presentation

Neonatal infection - small but definite risk - increased by vaginal examination, presence of GBSand increased duration of rupture. Therefore, sterile speculum but don’t do VE

Question 21

What needs checking in PROM?

Answer 21

Lie and presentation - vaginal examination is usually avoided, but may be performed in a sterile manner if there is risk of cord prolapse - foetal auscultation or CTG are performed

Question 22

What are the management options of PROM?

Answer 22

admission
regular observations to ensure chorioamnionitis is not developing
oral erythromycin should be given for 10 days
antenatal corticosteroids
delivery should be considered at 34 weeks of gestation - there is a trade-off between increased risk of maternal chorioamnionitis with a decreased risk of respiratory distress syndrome as the pregnancy progresses