Management of Labour Flashcards
What is labour?
process of uterine contractions and cervical dilatation that enables the uterus to deliver the viable foetus (>24wks), placenta and membranes
What is the Dx of labour?
regular and increasing painful uterine contractions
that brings about progressive cervical effacement and/or dilatation
What is cervical effacement?
thinning and softening of cervix
What are the theories proposed for labour initiation?
- withdrawal of Progesterone
- neuronal stimulation from pressure on cervix
- CRH placental clock
- inflammatory process in cervix
POORLY UNDERSTOOD
What are the main stages of labour?
FIRST STAGE
period between onset of regular painful uterine contractions to full cervical dilatation
SECOND STAGE
from full cervical dilatation to delivery of foetus
<1hr in nulliparous
<30’ in multiparous
THIRD STAGE
from delivery of the foetus to delivery of the placenta and membranes
<15’ with active Mx of third stage of labour
What constitutes active management in labour?
oxytocin injection
physical retrieval of placenta
usually done when there are risk factors for passive Mx e.g. PPH, multiple babies
What are the phases in the 1st stage of labour?
- latent
- active
What is defined as the latent phase of first stage of labour?
- duration for cervix to become effaced (from 3cm long to <0.5cm)
- also cervical dilation to 3cm
With regular uterine contractions
- 6-8hr in nulliparous
- 4-6hr in multiparous
What is defined as the active phase of first stage of labour?
- duration for cervix to dilate from 3cm to 10cm (full dilated)
- rate of cervical dilation is 0.5cm/hr on average
What is a partogram?
graphical representation of the process of labour
What info is included in a partogram?
- rate of cervical dilatation
- descent of head
- contraction frequency + duration
- foetal HR
- liquor colour and quality
- caput and moulding foetal head
- maternal obs (temp, HR, BP, urine output, urine dip)
What is liquor in labour?
another name for amniotic fluid
How is the descent of the head monitored in labour?
done in relation to 1/5s of the head that is palpable above the pelvic brim or ischial spine of mother
What is the risk of too many contractions in a short space of time during labour?
baby will not be adequately perfused (= hyperstimulation)
Rx: reduce rate of oxytocin infusion or start terbutaline (reversal agent)
What are the terms for the aspects of the foetal head?
occiput: back of head
sinciput: front of head (forehead)
Why is the foetal occiput important in assessing labour progression?
- main defining marker used in digital examination of cervix
- used to assess for descent of head
- ‘anterior occiput’ position of baby creates smaller diameter, so easier for baby to deliver through maternal pelvis
What is an ALERT LINE in labour?
a line drawn at rate of 1cm/hr from the admission cervical dilatation in the active phase
if labour is not progressing well this is when HCP should be alert, Mx may need to be considered
What is an ACTION LINE in labour?
a line drawn 4cm to the right and parallel to the alert line
if labour progresses to the right of the action line, then it is slow and needs some intervention
What is the mechanism of labour?
- baby enters pelvis with head in occipito-transverse
- descent with head in flexion
- internal rotation of head
- extension of head (crowning)
- restitution to deliver the posterior shoulder (external rotation)
- delivery of the anterior shoulder and body
What are the main problems that can arise from first stage of labour?
- slow labour
Mx
- partogram/action line: monitor foetus, mother, progress of labour
- titrate oxytocin infusion
- artificial rupture of membranes (ARM)
What are the causes of slow labour in 1st stage?
3 P’s
PASSAGE
short stature, previous pelvic injury, soft/bony tumour
PASSENGER
baby too big or malpresentation
since labour is dynamic, may see abnormal flexion on moulding etc of baby (head)
POWER
most common
What is done for admission in labour?
ASSESSMENT
- high or low risk
- team management
DEFINITIVE Dx OF LABOUR
- may be difficult
- may need to be observed
What management of active phase labour can be done?
- reassurance
- hydration
- adequate pain relief (NOS, pethidine)
- emotional support essential
- midwife-led care NORMAL
- be prepared for emergency, consult when required
- artificial rupture of membranes (ARM)
- judicious use of oxytocin with foetal surveillance
- CTG: can monitor foetal HR and frequency of contractions, but not strength of contractions
What is CTG and what can it indicate in labour?
= continuous cardiotocography
monitors foetal HR and contraction frequency (but not strength of contractions)
acceleration of HR
deceleration of HR: usually due to placental insufficiency or cord compression)
variability of CTG foetal HR: can indicated impaired foetal brain function e.g. acidosis, hypoxia etc
What are the consequences of slow labour (in 1st stage)?
- foetal distress
- haemorrhage (PPH)
- LSCS
- maternal/foetal exhaustion
- chorio-amnionitis: infection caused by repeated bimanual examination during delivery
- vesico-vaginal fistula
What Mx can be used in slow labour?
- IV Oxytocin
if 6-8hr and no progress, then = prolonged labour. alternative Mx may need to be used - consider terbutaline and emergency C-section
What are the main considerations with IV oxytocin in labour?
titrate dose, note that too much can cause uterine rupture
supplemented with fluids, since oxytocin has ADH effect
note that fluid overload can cause seizures etc with prolonged fluid use
What is dystocia in delivery?
baby getting stuck, e.g. often by the shoulder on the pubic bone (shoulder dystocia)
failure of delivery of the foetal head is usually an indicator as well as slow labour progression
What physiological changes are present for the second stage of labour?
- vulval bulging and gaping
- anal dilatation
- urge to push
- increased RR
- unable to sit still
- ‘in the zone’ or ‘lost the plot’
How long does the second stage of labour take?
2hr nullipara
1hr multipara
+epidural: 2hr passive descent after full dilation and then active pushing
-epidural: 1hr
What are the main problems encountered in the second stage of delivery?
PROLONGED SECOND STAGE
- nullip vs multip
- epidural vs no epidural
- active pushing vs not
- maternal exhaustion vs distress
- failure to descent/rotate
Mx: Ventouse, forceps
What are the considerations if trying an assisted vaginal delivery?
- head should be 0/5 or 1/5th palpable
- no obstruction (e.g. dystocia)
- empty bladder
- membranes ruptures
What active management is used in the third stage of labour?
- IM syntometrine given to mum @ delivery of anterior shoulder
- left hand placed above symphysis pubis to guard anterior all of uterus
- controlled cord traction until placenta is delivered
- placenta and membranes checked for completeness
- estimate blood loss
- check for tears and sutures under local if needed
What are the main problems in third stage of labour?
- retained placenta
- PPH (need to consider cause)
- perineal trauma (2nd-4th degree tear)
- perineal / pelvic haematoma
- uterine inversion
