Normal labour Flashcards
What is labour?
Labour is the process in which the fetus, placenta and membranes are expelled via the birth canal.
When does normal labour occur?
37-42 weeks gestation
What is the normal lie during normal labour?
Vertex
Two key physiological changes must occur to allow for expulsion of the fetus, what are these?
1) Cervix softens
2) Myometrial tone changes to allow for coordinated contractions
3) Progesterone decreases whilst oxytocin and prostaglandins increase to allow for labour to initiate
Which two synthetic hormones can be used to augment and induce labour?
1) Synthetic oxytocin
2) Prostoglandins
What happens in the latent first stage of labour?
A period during which there are intermittent, often irregular, painful contractions which bring about some cervical effacement and dilatation up to 4cm.
What happens in the established first stage of labour?
Regular, painful contractions that result in progressive effacement and cervical dilatation from 4cm.
When is the first stage of labour complete?
When the cervix is fully dilated (10cm)
How long is the average length of established first stage of labour?
8 hours, it is unlikely to last longer than 18 hours
What is the anticipated progress in terms of dilation
0.5 – 1.0 cm dilatation per hour
How do we refer to the size of the cervix?
Fruits: > 1cm-2cm = grape > 3cm = Strawberry > 4cm = Banana > 5cm = Lime > 6cm = Kiwi > 7-8cm = Apple > 9cm = Orange > 10cm = Melon
When does stage II of Labour begin?
When full cervical dilatation (10 cm) has occurred
What does stage II of labour begin ?
From full cervical dilatation to the birth of the baby
What is the Passive second stage of labour?
The finding of full dilatation of the cervix before or in the absence of involuntary expulsive contractions.
Plan to allow one hour of passive second stage to allow for further fetal descent.
What is the Active second stage of labour?
1) The presenting part is visible.
2) Expulsive contractions with a finding of full dilatation of the cervix.
3) Active maternal effort following confirmation of full dilatation of the cervix in the absence of expulsive contractions.
Within primigravida birth, from active stage II of labour when would you expect birth?
Within two hours of active second stage commencing
Within multigravida birth, from active stage II of labour when would you expect birth?
Within one hours of active second stage commencing
What is multigravida birth?
When a woman has given pregnant at more than twice
What is grand multigravida birth?
Grand multigravida is a woman who has had six or more previous pregnancies.
What is the third stage of labour?
The third stage of labour is the time from the birth of the baby to the expulsion of the placenta and membranes.
Active management of the third stage involves a package of care comprising the following component?
> Routine use of uterotonic drugs
> Deferred clamping and cutting of the cord
> Controlled cord traction after signs of separation of the placenta.
Physiological management of the third stage involves a package of care that includes the following components?
> No routine use of uterotonic drugs
> No clamping of the cord until pulsation has stopped
> Delivery of the placenta by maternal effort
Diagnose a prolonged third stage of labour if it is not completed within what time frame?
1) Active management = 30 minutes
2) Physiological management = 60 minutes
What is monitored throughout labour?
1) Blood pressure, pulse, temperature, respirations, oxygen saturation, urine output and urinalysis
2) Abdominal palpation
3) Vaginal examination
4) Monitoring of liquor (colour, smell, volume) once spontaneous or artificial rupture of membranes has occurred.
5) Auscultation of the fetal heart
6) Palpation of uterine muscle contractions
7) External signs e.g. Rhomboid of Michaelis and anal cleft line
What is monitored throughout labour - Abdominal palpation?
Used to assess fetal lie, presentation, attitude, denominator, position and engagement
What is monitored throughout labour - Vaginal examination?
Used to assess:
1) Presentation
2) Engagement and station
3) Position
4) Cervical effacement and dilatation and presence/ absence of membranes
What is monitored throughout labour - Auscultation of the fetal heart?
> Either intermittently with hand held Doppler or Pinards, or continuously with CTG (cardiotocograph) monitoring.
> Intermittent monitoring is undertaken every 15 minutes in the first stage of labour and every 5 minutes in the second stage of labour.
What is monitored throughout labour - Palpation of uterine muscle contractions?
Aiming for 3-4 every 10 minutes, lasting approximately 40-60 seconds moderate to strong in strength
Types of fetal presentation?
1) Face
2) Brow
3) Vertex
4) Breech
5) Shoulder
Types of fetal lie?
1) Longitudinal
2) transverse
3) Oblique
How large is the occipitofrontal plane of the fetal skull?
11.75cm
How large is the submentobregmatic plane of the fetal skull?
9.5cm
How large is the suboccipitobregmatic plane of the fetal skull?
9.5cm
How large is the occipitomental plane of the fetal skull?
13.5cm
The position in normal labour is determined in relation to what?
The position is determined in relation to the occiput (posterior fontanelle)
The mechanism of labour?
1) Descent
2) Flexion
3) Internal rotation of the head
4) Crowning and extension of the head
5) Restitution
6) Internal rotation of the shoulders
7) External rotation of the head
8) Lateral flexion
In normal labour what is the: - Lie - Attitude - Presentation - Position - Denominator - Presenting part ?
- Lie = Longitudinal
- Attitude = Good flexion
- Presentation = Cephalic
- Position = LOA or ROA
- Denominator = Occiput
- Presenting part = Anterior parietal bone
Analgesia in labour?
1) Breathing, massage, TENS, paracetamol and dihydrocodeine
2) Water
3) Entonox (inhalational nitrous oxide and oxygen)
4) Opioids (morphine, diamorphine, pethidine)
5) Remifentanil patient controlled analgesia
6) Epidural
7) Consider maternal position and mobility as means of reducing pain and facilitating progress in labour
Analgesia in labour - Entonox?
Inhalation nitrous oxide and oxygen
Analgesia in labour - Opiods?
> Morphine
Diamorphine
Pethidine
