Normal Labour

Question 1

What is labour?

Answer 1

Labour is the process in which the foetus, placenta and membranes are expelled via the birth canal.

Question 2

When does normal labour usually occur

Answer 2

In normal labour occurs spontaneously, at term (37-42 weeks gestation), with the foetus presenting by the vertex and results in a spontaneous vaginal birth (SVD)

Question 3

How is labour triggered?

Answer 3

By paracrine and autocrine signals generated by maternal, foetal and placental factors which interplay

Question 4

What are the key physiological changes which must occur before expulsion of the foetus will occur?

Answer 4

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

Question 5

What is the latent first stage of labour?

Answer 5

• longest part
• intermittent, often irregular painful contractions
• which bring about some cervical effacement and dilatation up to 4cm

Question 6

What is the active first stage of labour?

Answer 6

• regular, painful contractions

- result in progressive effacement and cervical dilatation from 4cm

Question 7

When is the first stage of labour complete?

Answer 7

When the cervix is fully dilated (10cm)

Question 8

How long does the first stage of labour last?

Answer 8

varies between women

• for a primagravida: avg. 8 hours (unlikely to last longer than 18 hours)
• for a multigravida: avg. 5 hours (unlikely to last over 12 hours).

Question 9

How fast does the first stage of labour progress?

Answer 9

0.5-1cm per hour

Question 10

How does the cervix thin and dilate?

Answer 10

uterine contractions

• start at the fundus and move down and across
• exert pressure on fetal pole
• encourages flexion
• pressure on the cervix to thin and dilate

Question 11

What does stage 2 of labour encompass?

Answer 11

From full cervical dilatation to the birth of the baby

Question 12

What is the passive second stage of labour?

Answer 12

full dilatation of the cervix

before or in the absence of involuntary expulsive contractions

Question 13

What is the active second stage of labour?

Answer 13

expulsive contractions with a finding of full dilatation of the cervix

Question 14

How long should the second stage of labour last?

Answer 14

primagravida birth: two hours

multigravida birth: one hour

Question 15

What is the third stage of labour?

Answer 15

Time from the birth of the baby to the expulsion of the placenta and membranes

Question 16

What does active management of the third stage of labour involve?

Answer 16

Package of care

• uterotonic drugs
• deferred clamping and cutting of the cord
• controlled cord traction after signs of separation of the placenta

Question 17

What does physiological management of the third stage of labour involve?

Answer 17

Package of care

• No routine use of uterotonic drugs
• No clamping of the cord until pulsation has stopped
• Delivery of the placenta by maternal effort

Question 18

When is the third stage of labour considered delayed?

Answer 18

• If not completed within 30 minutes of the birth with active management
• If not completed within 60 minutes of the birth with physiological managemnet

Question 19

How should progress be monitored during labour?

Answer 19

• maternal observations: blood pressure, pulse, temperature, respirations, oxygen saturation, urine output and urinalysis
• abdominal palpation
• vaginal examination
• monitoring of liquor
• auscultation of the foetal heart
• palpation of the uterine muscle contractions
• external signs

Question 20

What is abdominal palpation used to assess?

Answer 20

• foetal lie
• foetal presentation
• foetal position
• foetal engagement

Question 21

What is vaginal examination used to assess?

Answer 21

• foetal presentation
• foetal position
• engagement and station
• cervical effacement and dilatation
• presence/ absence of membranes

Question 22

How is the foetal heart auscultated

Answer 22

• Intermittently with handheld Doppler or Pinards

- Continuosly with CTG

Question 23

When is intermittent monitoring of babies heartbeat carried out?

Answer 23

• Every 15 minutes in the first stage of labour

- Every 5 minutes in the second stage of labour

Question 24

Where should information be recorded during labour?

Answer 24

Partogram

Question 25

What uterine muscle contractions should be aimed for?

Answer 25

4 - 5 every 10 minutes lasting approximately 40-60 seconds of moderate to strong strength

Question 26

Give examples of foetal lie.

Answer 26

- Longitudinal lie (vertex or breech) - Oblique lie - Transverse lie

Question 27

Give examples of foetal presentation.

Answer 27

- Face presentation - Brow presentation - Vertex presentation - Breech presentation - Shoulder presentation

Question 28

Give examples of foetal attitude.

Answer 28

- Occipitofrontal - Submentobregmatic - Occipitotomental - Subccipitobregmatic

Question 29

What is position of foetus determined in relation to?

Answer 29

Occipitut (posterior fontanelle)

Question 30

What is the mechanism of labour?

Answer 30

- Descent - Flexion - Internal rotation of the head - Crowning and extension of the head - Restitution - Internal rotation of the shoulders - External rotation of the head - Lateral flexion

Question 31

What types of analgesia can be used in labour?

Answer 31

- maternal position and mobility - breathing, massage, TENS, paracetamol and dihydrocodeine - water - entonox (inhalational nitrous oxide and oxygen) - opioids (morphine, diamorphine, pethidine) - remifentanil patient controlled analgesia - epidural