Special circumstances

Question 1

What is ‘Bishops score’?

Answer 1

A score of the ‘favourability’ of the cervix to be induced. This is dependent on the effacement, early dilatation, how low the head is in the pelvis (station), consistency of the cervix, cervical position (anterior/posterior).

Question 2

How is induction carried out?

Answer 2

Prostaglandin E2 as a gel or slow-release preparation is inserted into the posterior vaginal fornix. This either starts labour or the ‘ripeness’ of the cervix is improved to allow amniotomy.
The forewaters are ruptures with an amnihook (artificial rupture of the membranes).
An oxytocin infusion is usually started within 2 hours if labour has not ensued.
(Oxytocin is often used alone if spontaneous rupture of the membranes has already occurred).

Question 3

What is the natural way of inducting?

Answer 3

Cervical membrane sweeping.
You pass 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.

Question 4

What are some of the indications for induction?

Answer 4

Foetal indications:

• prolonged pregnancy
• suspected IUGR
• antepartum haemorrhage
• prelabour term rupture of the membranes

Materno-foetal indications:

• Pre-eclampsia
• Diabetes

Maternal indications:

• social reasons
• in utero death

Question 5

What are the absolute and relative contraindications for induction?

Answer 5

Absolute contraindications:

• Foetal compromise (including abnormal CTG)
• Placenta praevia
• Abnormal lie
• Pelvic obstruction (mass)
• More than one previous caesarian section

Relative contraindication:
- One previous caesarian section

Question 6

What is the management of induced labour?

Answer 6

1 hour of CTG 1 hour after prostaglandins or when they stimulate uterine activity.
Oxytocin requires CTG monitoring.

Question 7

What are the complications of induced labour?

Answer 7

1. Inefficient uterine activity
2. Hyperstimulation of the uterine muscles causes foetal distress and even uterine rupture.
3. Postpartum haemorrhage and infection is more likely
4. Instrumental delivery/c-sections are more common

Question 8

What are the contraindications for a vaginal birth after caesarian?

Answer 8

• If the uterine scar is vertical
• any absolute indications for c-section
• previous uterine rupture
• multiple caesarian sections.

Question 9

What the most safe options for the mother after a caesarian section?

Answer 9

Most safe = vaginal birth
Between = elective caesarian
Least safe = emergency caesarian

Question 10

What are predictors of success of a vaginal birth?

Answer 10

Spontaneous labour
Interpregnancy interval less than 2 years
Low age
Low BMI
Caucasian
Previous vaginal delivery
When there has been a previous caesarian this has been elective (abnormal lie, placenta praevia) or for foetal distress, rather than because of dystocia.

Question 11

What happens when membranes rupture?

Answer 11

Gush and then uncontrollable trickle of clear liquid

Question 12

What are the risks of prelabour term rupture of the membranes?

Answer 12

Cord prolapse - rare and usually a complication of transverse lie or breech presentation.
Neonatal infection - risk is further increased by group B strep, vaginal examination and prolonged membrane rupture before labour.

Question 13

How is prelabour term rupture of the membranes managed?

Answer 13

CTG is performed.
Waiting - up to 24 hours with maternal pulse, temperature and foetal HR measured every 4 hours. The presence of meconium/evidence of infection warrants immediate induction.
Induction - associated with lower risk of the baby being taken to the neonatal unit. This policy is therefore slightly safer.