Normal Labour + Birth

Question 1

What is normal labour?

Answer 1

Process in which the fetus, placenta and membranes are expelled via the birth canal
Spontaneous at 37-42 weeks

Question 2

What causes the initiation of labour?

Answer 2

Process is not known

Triggered by para/auto-crine signals generated by maternal, fetal and placental factors

Question 3

What are the key changes that allow for the expulsion of the fetus?

Answer 3

• Cervix softens
• Myometrial tone changes to allow for coordinated contractions
• Progesterone decreases and oxytocin and prostaglandins increase to allow for labour to initiate

Question 4

What is Stage I of labour?

Answer 4

Latent and active first stage of labour
Completed when the cervix is 10cm dilated
Length of first stage varies
Anticipated progress = 0.5-1cm dilation per hour

Question 5

What is Stage II of labour?

Answer 5

From full cervical dilation to the birth of the baby
There is passive and active 2nd stage
Primagrvida = within 2hrs
Multigravida = within 1hr

Question 6

What is Stage III of labour?

Answer 6

From the birth of the baby to the expulsion of the placenta and membranes
There can be active or physiological management of this stage
Prolonged = more than 30mins with active or 60mins of physiological management

Question 7

What is CTG monitoring?

Answer 7

Continuous cardiotocography

Monitors heartbeat and number of contractions (nothing about the strength of contractions)

Question 8

What is the normal fetal heart beat?

Answer 8

110-160 BPM

Question 9

What is the normal head position for birth?

Answer 9

Cephalic presentation with the occiput anterior

Question 10

What are the mechanisms of labour?

Answer 10

1. Descent
2. Flexion
3. Internal rotation of the head
4. Crowing and extension of the head
5. Restitution
6. Internal rotation of the shoulders
7. External rotation of the head
8. Lateral flexion