Normal Labour Flashcards
Definition of Labour
The process by which the foetus, placenta and membranes are expelled via the birth canal
Term of labour occurs at how many weeks gestation?
37-42 weeks
The 3 key physiological changes that occur to allow for expansion of the foetus
- Cervix softens
- Myometrial tone changes to allow for coordinated contractions
- Progesterone decreases whilst oxytocin and prostaglandins increase to allow for labour to initiate
Cervix changes for expulsion of the foetus
From supportive role to birth canal Softens Effaces Thins out (paper thin) Moves forward from being quite posterior Dilate
How many stages of labour are there?
3
Substages of Stage 1 of Labour
Latent stage
Established stage
What does the latent stage of stage 1 involve?
Intermittent, often irregular painful contractions which bring about some cervical effacement and dilatation up to 4cm
Does everyone experience the first latent stage?
No
What does the established first stage 1 involve?
Regular, painful contractions that result in progressive effacement and cervical dilatation from 4cm (WHO says 5cm)
How long does the established stage last in primigravida mothers?
On average 8 hours
Unlikely to last longer than 18 hours
How long does the established stage last in multigravida mothers?
On average 5 hours
Unlikely to last over 2 hours
Where do the uterine contractions start?
The fundus of the uterus
How does the cervix dilate?
Uterine contractions move across
This exerts pressure on the foetal pole which encourages flexion and a well applied presenting part
Which in turn puts pressure on the cervix to thin and dilate
Anticipated progress of cervix dilation
0.5-1.0cm per hour
How often do you do a vaginal exam during labour?
every 4 hours
The cervix is fully dilated at….
10cm
When is the established first stage of labour complete?
When the cervix is fully dilated at 10cm
Substages of the second stage of labour
Passive stage
Active stage
Definition of Stage II of Labour
From full cervical dilatation to the birth of the baby
Passive Second stage of Labour involves
Finding of full dilatation of the cervix before or in the absence of involuntary expulsive contractions
What may women want to do in the passive second stage of labour?
May want to move around/change position
This means the baby is about to descend
How does the passive stage last?
1 hour to allow further foetal descent
The active second stage of labour involves
Active maternal effort (expulsive contractions) following confirmation of full dilatation of the cervix in the absence of expulsive contractions
Which substage of the second stage of labour is the presenting part visible?
Active stage
How long does the active stage of stage II of labour last in primigravida women?
Within two hours of the active stage commencing
How long does the active stage of II of labour last in multigravida women?
Within one hour of the active stage commencing
Definition of the Stage III of Labour
The time of birth of the baby to the expulsion of the placenta and membranes
What happens to the placenta as the baby is born?
It folds in on itself and is covered by the membranes
What can happen to the membranes in the third stage of labour?
Can rupture spontaneously
Can be ruptured artificially e.g. by a hook
Two types of management for stage III
Active management
Physiological management
Active management of stage III involves
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 Stage III involves
No clamping of the cord until pulsating has stopped
No use of uterotonic drugs
Delivery of placenta by maternal effort
How long does it take to diagnose a prolonged third stage of labour?
In active management = within 30 mins of birth
In physiological management = within 60 mins of birth
MOEWS
Modified obstetric early warning score
Progress and monitoring of labour done by
MOEWS BP HR Temp Respirations, O2 sats urine output and urinalysis abdominal palpation (PRIOR TO VE) Vaginal examination Monitoring of liquor (colour, smell, volume) once rupture of membranes has occurred Auscultation of foetal heart Palpation of uterine muscle contractions External signs e.g. Rhomboid of Michaelis and Anal cleft line
Before what does abdominal palpation ALWAYS have to be done
Vaginal Examination
What does abdominal palpation look at?
Foetal lie presentation altitude denominator position engagement
What does vaginal exam look at?
Presentation engagement station position cervical effacement and dilatation presence/absence of membranes
How to auscultate the foetal heart
Intermittedly with hand held doppler
pinards
continuously with CIG (cardiotocograph)
How often to intermittendly monitor the babys heart
1st stage of labour = every 15 mins
2nd stage of labour = every 5 mins
Active phase = try after every contraction
If the baby’s heart increases from baseline, this means….
Infection
If the baby’s heart decreases from baseline, this means…..
Stress
How many contractions are normal?
3-4 every 10 mins, lasting 40-60 seconds
Moderate to strong in strength
What is the Rhomboid of Michaelis?
The baby puts pressure on the lower sacrum and you can see this - its easier to see in slimmer women
What is the anal cleft line?
Purple line that appears in the second stage due to the pressure (from a reddish colour)
Different possible presentations of the foetus
Face Brow Vertex Breach Shoulder
Position in normal labour is the position in relation to the
Occiput (posterior fontanelle)
The mechanism of labour and changes of the position of the body
- Descent and flexion
- Internal rotation of the head
- Crowning and extension of the head
- Restitution (turns)
- Internal rotation of the shoulders
- External rotation of the head
- Lateral flexion
Position of normal labour
LOA or ROA
Lie of normal labour
Longitudinal lie
Presentation of normal labour
Vertex and cephalic presentation
Denominator in normal labour is the….
Occiput
Which bone is meant to be the presenting part of the foetus?
Anterior parietal bone
Analgesics used in labour
Breathing, massage, paracetamol dihydrocodeine Water Entonox (nitrous oxide + oxygen inhaled) Opoids (morphine, diamorphine, pethidine) Epidural Reminifentanil patient controlled analgesia Maternal position and mobility Continous midwifery Birthing balls, baths and pools
Mechanisms of labour
Engagement Descent Flexion Internal rotation Extension Restitution and external rotation Expulsion
Indications for C section
Absaloute CPD Placenta praevia grades 3 / 4 Pre eclampsia Post maturity IUGR Foetal distress in labour / prolapsed cord Failure to progress in labour Malpresentations; brow Placental abruption if foetal distress Vaginal infection e.g. active herpes Cervical cancer
Serious complications of C sections
Emergency hysterectomy Need for further surgery at a later date Thromboembolic disease ITU admission Bladder or ureteric injury Death 1 in 12 000 Future pregnancies - Increased risk of uterine rupture - increased risk of antepartum stillbirth - increased risk of pregancies with placenta praevia and placenta accreta
Frequent complications of C sections
Persistent wound and abdo discomfort in 1st few months
Increased risk of C section in subsequent pregnancies
Readmission to hosp
Haemorrhage
Infection
Foetal lacerations 1 - 2 babies per 100
