Normal Labour

Question 1

What is labour?

Answer 1

The process via which the foetus, placenta and membranes are expelled via the birth canal

Question 2

What are some of the defining characteristics of normal labour?

Answer 2

• Occurs spontaneously (not induced)
• Occurs at 37-42 weeks gestation
• Fetus presents by the vertex (head down)
• Results in a spontaneous vaginal birth

Question 3

What are some of the cervical and uterine changes that occur as labour initiates?

Answer 3

Cervix softens

Myometrial tone of the uterus changes to allow for coordinated contractions

Question 4

What are some of the hormonal changes that occur at the initiation of labour?

Answer 4

• Progesterone decreases

- Oxytocin and prostaglandins increase

Question 5

How many stages of labour are there? What does each stage encompass?

Answer 5

First stage - early / latent phase, active first stage and transition

Second stage - passive and active second stage

Third stage - active / physiological stage

Question 6

What is the longest phase of labour that the woman will encounter? What characterizes this stage?

Answer 6

The latent phase of the first stage - can be up to days in length

Irregular contractions start, they are quite short lasting.

There is also shortening, thinning, anterior movement and dilatation up to 4cm of the cervix

Question 7

What characterizes the active first stage of labour? How long does this stage last?

Answer 7

• Cervix dilating from 4cm to 10cm
• Regular, painful contractions (3-4 contractions per 10 minutes, all lasting about a minute)

Stage lasts about 8-12 hours

Question 8

What characterizes the transition phase of the first stage of labour?

Answer 8

Cervix dilated 8-10cm

Physical changes:

• Patient may start to shake
• Feel the urge to vomit / empty bowels
• Express need for pain relief / feels she can’t cope

Question 9

What characterizes the passive phase of the second stage of labour?

Answer 9

• Being fully dilated to the birth of the baby

- Involuntary expulsive contractions yet to start

Question 10

What characterizes the active phase of the second stage of labour?

Answer 10

• Expulsive contractions begin / maternal effort to expel the baby
• May see partial presentation of the baby

Question 11

How long does the second stage of labour last?

Answer 11

Usually 2-3 hours

Question 12

What is an important factor that can affect the length of each of the first two stages of labour?

Answer 12

Whether the woman is nulliparous or multiparous

Nulliparous - never given birth before, or only to a stillborn baby
Multiparous - has given birth before

Question 13

What characterizes the third stage of labour?

Answer 13

Includes birth of the baby and the expulsion of the placenta and membranes

Question 14

What are the two options for managing the third stages of labour?

Answer 14

Physiological management: no drugs, clamping and placenta delivered by maternal effort

Active management:

• Uterotonic drugs
• Cord clamping
• Expulsion of placenta by cord traction

Question 15

How long does the third stage of labour last?

Answer 15

Actively managed - completed within 30 minutes

Physiologically managed - within 60 minutes

Question 16

How does contraction and retraction of the uterine wall facilitate delivery?

Answer 16

Creates a smaller volume in the uterus, increased pressure pushes baby out

Reduces diameter of the uterus to direct the baby through the pelvis

Question 17

In which direction does the baby rotate during delivery? What causes this rotation?

Answer 17

Rotates internally

Resistance from the diaphragm along with the shape of the pelvis causes this rotation, moving the baby into a more optimal position for childbirth

Question 18

When does crowning occur during childbirth?

Answer 18

When the occiput (back of head) slips below the pubic arch and the head no longer recedes backwards

(when you can see the top of the baby’s head)

Question 19

What are the extension and restitution mechanisms of labour?

Answer 19

Extension - baby’s full head past the pubic arch, see the brow face and chin born over perineum

Restitution - baby’s head rotates to put it back in plane with rest of body

Question 20

List the mechanisms of labour in order

Answer 20

• Engagement and descent
• Flexion
• Internal rotation of head
• Crowning and extension of head
• Restitution
• Internal and external rotation of head
• Lateral flexion of shoulders

Question 21

What are the different types of fetal lie?

Answer 21

Cephalic / vertex - head towards pelvis, vertical

Breech - Buttocks towards pelvis, vertical

Transverse lie - horizontal lie of baby within uterus

Question 22

What are the different types of fetal presentation?

Answer 22

Face presentation - Face of baby facing the vaginal opening

Brow presentation - Crown of baby’s head facing vagina

Shoulder presentation - Shoulder of baby facing the pelvic opening

Question 23

What are the different fetal positions?

Answer 23

• Left occipital transverse / anterior / posterior

- Right occipital transverse / anterior / posterior

Question 24

What is used to perform intermittent auscultation of the fetus’ heart rate? When is this done?

Answer 24

Pinards stethoscope or Hand held Doppler

Every 15 minutes for a full minute following a contraction in first stage of labour, every 5 minutes or after every contraction in second stage

Question 25

Advantage of a hand held doppler over a pinards stethoscope?

Answer 25

Hand held doppler amplifies fetal heart rate so everyone in the room can hear it, only midwife can hear it with the Pinards stethoscope

Question 26

What is the normal fetal heart rate?

Answer 26

110-160 bpm Lots of variability (>5 bpm) Often have accelerations of around 15bpm

Question 27

What are some methods of monitoring maternal health during labour?

Answer 27

Maternal Observations - HR, BP, Temp etc. Abdominal palpation - position of the baby Vaginal examination - is mother dilated & position of baby Monitoring of amniotic fluid (amniotic liquor) - colour / content Palpation of contractions - palpate contractions for a 10 minute period every half hour, strength and tone External signs - eg. Rhomboid of Michaelis and anal cleft line

Question 28

What are some methods of supporting the mother through labour?

Answer 28

Maternal mobility and position - upright position and maintenance of mobility reduces pain Breathing, hyponobirthing techniques, massaging, aromatherapy TENS machines - encourages endorphin production & reduce pain signals Oral analgesia Pools / baths - water helps during first 2 stages Entonox / opioids Remifentanil PCA (patient controlled analgesia) / Epidurals